* add --transpileOnly flag

Ref #243

* Document --transpileOnly flag

* Make test check that stuff is build

* fix anchor id

* remove shorthand

* remove docs

- treeshake was in output, but it's not a config of output :/ :/ :/
  - once explicit types were added, this was a big red underline :/ :/

* Remove esnext target override from ts rollup config. Make es5 the default target.

* watch hooks

* Finished the hooks

* update readme

* move use strict

* fixed typo in watch help printout in README

* Remove esnext target override from ts rollup config. Make es5 the default target.

* watch hooks

* Finished the hooks

* update readme

*  update yarnlockfile

* Fix yarn.lock

Taken from here: #319 (comment)

* chore(package): update @types/node to version 13.1.0

* chore(package): update lockfile yarn.lock

- it was not clearly stated that CI=true was what needed to be added,
  so explicitly state that
- similarly, --color was an unnecessary option to pass and may have
  caused confusion, potentially making users believe that it was
  necessary in order to disable watch mode
  - also, --color does not seem to be a valid option of Jest, but
    --colors (note the s) is used to force highlighting in non-TTY

- also, properly format package.json example as JSON, including the
  "scripts" section
- and add a test:watch script for context, making more explicit the
  difference between non-watch and watch mode

- __DEV__ link stopped working
- Contributors link didn't work

- backtick formatting was removed

- this was all re-generated by using `npx doctoc README.md`
  - doctoc is specified to be used in the ToC comments

- this is done automatically when adding a dependency via Yarn / NPM
  - (but not when doing so manually)
  - format as separate commit so it won't need to be repeated or
    randomly introduced in others

- the React template and docs for it had --env=jsdom explicitly set,
  but there's no need to do this, as Jest uses JSDOM by default already

- setting it a second time in CLI also overrides any custom configs

- default is jsdom, which we don't need

- also fix missing newline at EOF

- better readability / changeability