Update babel-types docs, contributing, babel-cli [skip ci]

Closes gh-3684

CONTRIBUTING.md

@@ -55,14 +55,14 @@ $ make watch
 
 to have Babel build itself and incrementally build files on change.
 
+You can access the built files for individual packages from `packages/<package-name>/lib`.
+
 If you wish to build a copy of Babel for distribution, then run:
 
 ```sh
 $ make build-dist
 ```
 
-and access the files from `packages/babel-core/dist`.
-
 #### Running tests
 
 You can run tests for all packages via:

packages/babel-cli/README.md

@@ -2,6 +2,10 @@
 
 > Babel command line.
  
+In addition, various entry point scripts live in the top-level package at `babel-cli/bin`.
+
+There are some shell-executable utility scripts, `babel-doctor.js`, `babel-external-helpers.js` and `babel-node.js`, and the main Babel cli script, `babel.js`.
+
 ## Install
 
 ```sh

packages/babel-types/README.md

@@ -292,6 +292,14 @@ Aliases: `Flow`, `FlowDeclaration`, `Statement`, `Declaration`
  - `id` (required)
  - `body` (required)
 
+### t.declareModuleExports(typeAnnotation)
+
+See also `t.isDeclareModuleExports(node, opts)` and `t.assertDeclareModuleExports(node, opts)`.
+
+Aliases: `Flow`, `FlowDeclaration`, `Statement`, `Declaration`
+
+ - `typeAnnotation` (required)
+
 ### t.declareTypeAlias(id, typeParameters, right)
 
 See also `t.isDeclareTypeAlias(node, opts)` and `t.assertDeclareTypeAlias(node, opts)`.