[docs] Misc fixes

CHANGELOG.md

@@ -13123,7 +13123,7 @@ Shout out to @kybarg for the update of the `TextField` in order to better follow
 
 This release introduces an important change in the API and the implementation.
 Each exposed component is wrapped with a `withStyles` Higher-order component.
-This HOC has different responsibilities, the one you gonna be interested in is
+This HOC has different responsibilities, the one you're going to be interested in is
 regarding the `classes` property. Now, we consider the CSS as a public API.
 You now have two way to customize absolutely all the CSS injected by Material-UI.
 Either the instance level with the `classes` property or the class level with the
@@ -13136,8 +13136,9 @@ To learn more about it, have a look at the documentation.
 - [core] Various fixes after using it on a real project (#6882) @oliviertassinari
   Apply the other properties (undocumented) on the root of the Menu.
 - [core] Add a new classes property to all the components #6911 @oliviertassinari
-  If you where using the ref to access the internal of the component or native elements,
-  you gonna have to change your strategy, either use `innerRef` or `inputRef`.
+
+If you were using the ref to access the internals of the component or native elements,
+you're going to have to change your strategy. Either use `innerRef` or `inputRef`.
 
 #### Component Fixes / Enhancements
 
@@ -13574,9 +13575,9 @@ We are now at 93.53%. That's pretty great.
 
 ###### _Feb 7, 2017_
 
-One year from now, we were struggling with removing all the mixins from the project.
-Now, it's about rewriting all our components.
-We gonna try doing frequent alpha releases to keep some intertie. At least once per week would be good.
+One year ago, we were struggling with removing all the mixins from the project.
+Now, it's about rewriting all the components.
+We're going to try doing frequent alpha releases to keep some intertia. At least once per week would be good.
 As always, we are keeping the [documentation](https://material-ui.com) up to date.
 
 #### Component Fixes / Enhancements

docs/src/pages/components/button-group/button-group.md

@@ -12,14 +12,20 @@ githubLabel: 'component: ButtonGroup'
 
 ## Basic button group
 
+The standard Button variants are supported.
+
 {{"demo": "pages/components/button-group/BasicButtonGroup.js"}}
 
 ## Sizes and colors
 
+The `size` and `color` props can be used to control the appearance of the ButtonGroup.
+
 {{"demo": "pages/components/button-group/GroupSizesColors.js"}}
 
 ## Vertical group
 
+The ButtonGroup can be displayed veritcally using the `orientation` prop.
+
 {{"demo": "pages/components/button-group/GroupOrientation.js"}}
 
 ## Split button

docs/src/pages/components/lists/lists.md

@@ -86,7 +86,9 @@ Unfortunately it's [not implemented](https://caniuse.com/#search=sticky) by all
 
 {{"demo": "pages/components/lists/PinnedSubheaderList.js", "bg": true}}
 
-## Inset List
+## Inset List Item
+
+The `inset` prop enables a list item that does not have a leading icon or avatar to align correctly with items that do.
 
 {{"demo": "pages/components/lists/InsetList.js", "bg": true}}
 

docs/src/pages/components/modal/modal.md

@@ -36,6 +36,8 @@ Modal is a lower-level construct that is leveraged by the following components:
 
 ## Simple modal
 
+This demo stacks Modals, but it is strongly discouraged to do so in practice.
+
 {{"demo": "pages/components/modal/SimpleModal.js"}}
 
 Notice that you can disable the outline (often blue or gold) with the `outline: 0` CSS property.

docs/src/pages/components/transitions/transitions.md

@@ -6,15 +6,15 @@ githubLabel: 'component: Transition'
 
 # Transitions
 
-<p class="description">Transition helps make a UI expressive and easy to use.</p>
+<p class="description">Transitions help to make a UI expressive and easy to use.</p>
 
 Material-UI provides a number of transitions that can be used to introduce some basic
 [motion](https://material.io/design/motion/)
 to your applications components.
 
 {{"component": "modules/components/ComponentLinkHeader.js", "design": false}}
 
-To better support server rendering Material-UI provides a `style` prop to the children of some transition components (Fade, Grow, Zoom, Slide).
+To better support server rendering, Material-UI provides a `style` prop to the children of some transition components, (Fade, Grow, Zoom, Slide).
 The `style` prop must be applied to the DOM for the animation to work as expected.
 
 ```jsx
@@ -83,7 +83,7 @@ This example also demonstrates how to delay the enter transition.
 
 ## TransitionComponent prop
 
-The components accept a `TransitionComponent` prop to customize the default transitions.
+Some Material-UI components use these transitions internally. These accept a `TransitionComponent` prop to customize the default transition.
 You can use any of the above components or your own.
 It should respect the following conditions:
 

docs/src/pages/components/typography/typography.md

@@ -17,7 +17,7 @@ A [typographic scale](https://material.io/design/typography/#type-scale) has a l
 ## General
 
 The _Roboto_ font will **not** be automatically loaded by Material-UI.
-The developer is responsible for loading all fonts used in their application.
+You are responsible for loading any fonts used in your application.
 Roboto Font has a few easy ways to get started. For more advanced configuration, check out
 [the theme customization section](/customization/typography/).
 
@@ -54,6 +54,8 @@ Material-UI default typography configuration only relies on 300, 400, 500, and 7
 
 ## Component
 
+The Typography component makes it easy to apply a default set of font weights and sizes in your application.
+
 {{"demo": "pages/components/typography/Types.js"}}
 
 ## Theme

packages/material-ui/src/Slide/Slide.js

@@ -9,9 +9,8 @@ import { duration } from '../styles/transitions';
 import { reflow, getTransitionProps } from '../transitions/utils';
 import { ownerWindow } from '../utils';
 
-// Translate the node so he can't be seen on the screen.
-// Later, we gonna translate back the node to his original location
-// with `none`.`
+// Translate the node so it can't be seen on the screen.
+// Later, we're going to translate the node back to its original location with `none`.
 function getTranslateValue(direction, node) {
   const rect = node.getBoundingClientRect();
   const containerWindow = ownerWindow(node);

packages/material-ui/src/Toolbar/Toolbar.d.ts

@@ -8,7 +8,8 @@ export type ToolbarVariantDefaults = Record<'regular' | 'dense', true>;
 export interface ToolbarTypeMap<P = {}, D extends React.ElementType = 'div'> {
   props: P & {
     /**
-     * Toolbar children, usually a mixture of `IconButton`, `Button` and `Typography`.
+     * The Toolbar children, usually a mixture of `IconButton`, `Button` and `Typography`.
+     * The Toolbar is a flex container, allowing flex item properites to be used to lay out the children.
      */
     children?: React.ReactNode;
     /**

packages/material-ui/src/Toolbar/Toolbar.js

@@ -71,7 +71,8 @@ Toolbar.propTypes = {
   // |     To update them edit the d.ts file and run "yarn proptypes"     |
   // ----------------------------------------------------------------------
   /**
-   * Toolbar children, usually a mixture of `IconButton`, `Button` and `Typography`.
+   * The Toolbar children, usually a mixture of `IconButton`, `Button` and `Typography`.
+   * The Toolbar is a flex container, allowing flex item properites to be used to lay out the children.
    */
   children: PropTypes.node,
   /**