Update Features.md

Summary:
1. Sorts the entries
2. Add BigInt to ```Supported``` features.

Reviewed By: fbmal7

Differential Revision: D39829978

fbshipit-source-id: 4b7404c1b868baf604e2af3dd53900cfaea651cd

doc/Features.md

@@ -7,56 +7,56 @@ Hermes plans to target ECMAScript 2015 (ES6), with some carefully considered exc
 
 ### Supported
 
-- Symbols (including most well-known Symbols)
-- Iteration (with `[Symbol.iterator]`)
-- `for..of` loops
+- All ES6 JS library functions
+  - ES6 Array searching functions
+  - ES6 String searching functions
+  - Set/Map
+  - WeakSet/WeakMap
 - Array spread
-- Object rest/spread
-- Shorthand property and computed property on object literals
+- Arrow functions
+- BigInt
 - Destructuring assignment (with array and object "rest" properties)
-- Template string literals
+- ES6 Promise (with incompatibilities documented below)
+- `for..of` loops
 - Generators (`function*` and `yield`)
-- TypedArrays
-- Arrow functions
+- [`Intl`, or Internationalization APIs](IntlAPIs.md)
+- Iteration (with `[Symbol.iterator]`)
+- Object rest/spread
 - Optional chaining and nullish coalescing (`?.` and `??`)
 - Reflection (`Reflect` and `Proxy`) starting from [v0.7.0](https://github.com/facebook/hermes/releases/tag/v0.7.0)
-- [`Intl`, or Internationalization APIs](IntlAPIs.md)
-- ES6 Promise (with incompatibilities documented below)
-- All ES6 JS library functions
-  - Set/Map
-  - WeakSet/WeakMap
-  - ES6 String searching functions
-  - ES6 Array searching functions
+- Shorthand property and computed property on object literals
+- Symbols (including most well-known Symbols)
+- Template string literals
+- TypedArrays
 
 ### In Progress
 
-- WeakRef
-- BigInt
+- Async function (`async` and `await`).
 - ES modules (`import` and `export`)
 - `Intl` API glue has been added to enable community contribution of a complete, spec-compliant implementation on multiple platforms
-- Async function (`async` and `await`).
 - `Symbol.prototype.description` (it's not fully spec-conformant yet. `Symbol().description` should be `undefined` but it's currently `''`).
+- WeakRef
 
 ### Planned
-- RegExp match indices and named capture groups
-- Expanded Intl functionality (e.g., DisplayNames, ListFormat, PluralRules, RelativeTimeFormat, and Locale)
-- `let` and `const` (block scoped variables, with support for the temporal dead zone)
+- Block scoped variables (`let` and `const`), with support for the temporal dead zone
 - Classes and method definitions
+- Expanded Intl functionality (e.g., DisplayNames, ListFormat, PluralRules, RelativeTimeFormat, and Locale)
+- RegExp match indices and named capture groups
 
 ### Excluded From Support
 
-- Realms
-- `with` statements
 - Local mode `eval()` (use and introduce local variables)
+- Other features added to ECMAScript after ES6 not listed under "Supported"
+- Realms
 - `Symbol.species` and its interactions with JS library functions
-- use of `constructor` property when creating new Arrays in Array.prototype methods
 - `Symbol.unscopables` (Hermes does not support `with`)
-- Other features added to ECMAScript after ES6 not listed under "Supported"
+- use of `constructor` property when creating new Arrays in Array.prototype methods
+- `with` statements
 
 ### Miscellaneous Incompatibilities
 
-- `Function.prototype.toString` cannot show source because Hermes executes from bytecode
 - `arguments` changes in non-strict mode will not sync with named parameters
+- `Function.prototype.toString` cannot show source because Hermes executes from bytecode
 - `Promise` is implemented by pre-compiling [the JS polyfill from RN](https://github.com/facebook/react-native/blob/HEAD/Libraries/Promise.js) as the [internal bytecode](https://github.com/facebook/hermes/blob/HEAD/lib/InternalBytecode/Promise.js) to preserve the current interoperation, hence its conformance to the spec is up to conformance of the polyfill.
   - In case you want to bring in your own Promise and opt-out Hermes', you can turn it off by passing `-Xes6-promise=0` in CLI or setting `withES6Promise(false)` in the runtime configs.
   - N.B. ES6 Promise does not include `Promise.allSettled` (ES2020) and `Promise.any` (Stage 4).