Move wiki to repo

This commit does the following:
- Migrates all pages from the wiki that are linked to
- Fix links in all wiki pages and in ./README.md, ./CONTRIBUTING.md and
  ./test/README.md

Fixes #2480

wiki/contributing/coding-guidelines.md

@@ -0,0 +1,51 @@
+# Coding Guidelines
+
+## Git
+
+We prefer a **rebase workflow** and occasional **feature branches**. Most work happens directly on the `master` branch. For that reason, we recommend setting the `pull.rebase` setting to true.
+
+```
+git config --global pull.rebase true
+```
+
+## Indentation
+We use tabs, not spaces.
+
+## Names
+* Use PascalCase for `type` names
+* Use PascalCase for `enum` values
+* Use camelCase for `function` and `method` names
+* Use camelCase for `property` names and `local variables`
+* Use whole words in names when possible
+
+## Types
+* Do not export `types` or `functions` unless you need to share it across multiple components
+* Do not introduce new `types` or `values` to the global namespace
+
+## Comments
+* Use JSDoc style comments for `functions`, `interfaces`, `enums`, and `classes`
+
+## Strings
+* Use "double quotes" for strings shown to the user that need to be externalized (localized)
+* Use 'single quotes' otherwise
+* All strings visible to the user need to be externalized
+
+## Style
+* Use arrow functions `=>` over anonymous function expressions
+* Only surround arrow function parameters when necessary. For example, `(x) => x + x` is wrong but the following are correct:
+
+``` javascript
+  x => x + x
+  (x,y) => x + y
+  <T>(x: T, y: T) => x === y
+```
+
+* Always surround loop and conditional bodies with curly braces
+* Open curly braces always go on the same line as whatever necessitates them
+* Parenthesized constructs should have no surrounding whitespace. A single space follows commas, colons, and semicolons in those constructs. For example:
+
+``` javascript
+  for (var i = 0, n = str.length; i < 10; i++) { }
+  if (x < 10) { }
+  function f(x: number, y: string): void { }
+```