chore: migrate Travis CI to container-based builds and update README links

- Switch Travis CI from sudo-based apt-get to addons.apt.packages for gcc-multilib
- Enable container-based builds with `sudo: false`
- Update README.md call-to-action links to point to getting-started and browser playground
- Replace `printList_` with `printAll` in IO class and remove redundant `IO.` prefixes
- Add IO.read() method documentation and update IO.print docs for up to 16 arguments
- Reorganize community page with Libraries, Language bindings, and Tools sections
- Add wrenjs JavaScript binding and Sublime Text syntax highlighting
- Fix typo "no where" to "nowhere" in fibers documentation
- Add indentation to preprocessor defines in wren_common.h for consistency
- Remove unreachable `return 0` after UNREACHABLE() in wren_compiler.c
- Fix Windows color output by wrapping text in str() in test script

doc/site/fibers.markdown

@@ -113,7 +113,7 @@ of the `yield()` call:
 
 This prints "sent". Note that the first value sent to the fiber through call is
 ignored. That's because the fiber isn't waiting on a `yield()` call, so there's
-no where for the sent value to go.
+nowhere for the sent value to go.
 
 Fibers can also pass values *back* when they yield. If you pass an argument to
 `yield()`, that will become the return value of the `call` that was used to