incorporate collections spec into features spec

CHANGELOG.md

@@ -8,7 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
-- Browseable specification has been incorporated into the *STAC API - Core* specification.
+- The Collections specification has been incorporated into the *Features* specification, but remains as
+  a separate conformance class. 
+- The Browseable specification has been incorporated into the *Core* specification, but remains as
+  a separate conformance class.
 - Extensions moved to standalone specification repositories:
     - [Items and Collections API Version](https://github.com/stac-api-extensions/version) 
     - [Fields](https://github.com/stac-api-extensions/fields)

README.md

@@ -37,8 +37,8 @@ The SpatioTemporal Asset Catalog (STAC) family of specifications aim to standard
 A 'spatiotemporal asset' is any file that represents information about the Earth captured in a certain space and 
 time. The core STAC specifications live in the GitHub repository [radiantearth/stac-spec](https://github.com/radiantearth/stac-spec).
 
-A STAC API is a dynamic version of a SpatioTemporal Asset Catalog. This repository defines the four
-STAC API foundation specifications -- [STAC API - Core](core/), [STAC API - Collections](collections/),
+A STAC API is a dynamic version of a SpatioTemporal Asset Catalog. This repository defines the three
+STAC API foundation specifications -- [STAC API - Core](core/),
 [STAC API - Features](ogcapi-features/), and [STAC API - Item Search](item-search/) -- which can be composed 
 with [Extensions](extensions.md) to define a specific STAC API implementation.
 
@@ -104,9 +104,6 @@ The **[Overview](overview.md)** document describes all the various parts of the
 The *[core](core/)* folder describes the core STAC API specification that enables browsing catalogs and 
 retrieving the API capabilities. This includes the OpenAPI schemas for STAC Item, Catalog and Collection objects.
 
-**STAC API - Collections:**
-The *[collections](collections)* folder describes how a STAC API Catalog can advertise the Collections it contains.
-
 **STAC API - Features:**
 The *[ogcapi-features](ogcapi-features)* folder describes how a STAC API can fully implement [OGC API - 
 Features](http://docs.opengeospatial.org/is/17-069r3/17-069r3.html) to expose individual `items` endpoints for search of

children/README.md

@@ -57,8 +57,8 @@ array of Links in a field `links`.
 ## Pagination
 
 The `/children` endpoint supports a pagination mechanism that aligns with pagination as described in the 
-OGC API - Common - Part 2: Geospatial Data specification. This is described in detail in
-the [STAC - Features Collection Pagination section](../ogcapi-features/README.md#collection-pagination).
+[OGC API - Common - Part 2: Geospatial Data](https://portal.ogc.org/files/99149) specification. This is described in detail in
+the [STAC API - Features section on Collection Pagination](../ogcapi-features/README.md#collection-pagination).
 To the greatest extent possible, the catalog should be structured such that all children can be
 retrieved from the endpoint in a single call.
 

item-search/README.md

@@ -229,7 +229,7 @@ searching on specific Item properties.
 
 #### PUT / PATCH / DELETE
 
-The other HTTP verbs are not supported in STAC Item Search. The [Transaction Extension](../ogcapi-features/extensions/transaction/README.md)
+The other HTTP verbs are not supported in STAC Item Search. The [Transaction Extension](https://github.com/stac-api-extensions/transaction)
 does implement them, for STAC and OAFeat implementations that want to enable writing and deleting items.
 
 ## Example Landing Page for STAC API - Item Search