[major][guide][eslint config] Simplifies no-mixed-operators

[sharmilajesupaul]

• removes warning on mixing ** and arithmetic operators
• removes warning on mixing in and instanceof
• removes warning on mixing ~ with other bitwise operators
• removes mixing of assignment operators with comparison operators
• warn on mixing * and /

⚠️ working on guide update

fixed warnings:

// before 
const bar = a + b / c * d;

const bar1 = a * b / c * d;

const bar2 = a === b >> c !== d;

const bar3 = foo | c << d;

const bar4 = "foo" in b instanceof c;

// after 
const bar = a + (b / c) * d;

const bar1 = ((a * b) / c) * d;

const bar2 = (a === b >> c) !== d;

const bar3 = foo | (c << d);

const bar4 = 'foo' in b instanceof c;

[ljharb]

The description suggests that it only removes warnings; that suggests this is a patch. Confirm?

[sharmilajesupaul]

@ljharb there's actually one addition, to warn on mixing * and /, I updated the PR description and I'll update my commit to reflect that.

[sharmilajesupaul]

@ljharb updated the guide: https://github.com/airbnb/javascript/pull/1864/files?short_path=04c6e90#diff-04c6e90faac2675aa89e2176d2eec7d8

[ljharb]

LGTM! Holding off on merging this until #1834 is out.

[sharmilajesupaul]

@ljharb can we get this into the next breaking release?

[ljharb]

yep, i'm going to make a sweep before the next release and bring in all semver-majors.

[ljharb]

=it+is+time