[doclint] Move doclint under utils/

This patch:
- moves doclint under utils/ folder
- adds tests to verify doclint basic functionality

This patch also drops the jasmine as a spec runner for the doclint
checks. It turned out it's hard to customize jasmine's behavior,
so instead this patch implements a dummy spec runner.

The dummy spec runner allows us:
- to format messages however we want (the custom jasmine reporter would
  also allow us to do this)
- to avoid `beforeAll` functions which pollute global to pass
  initialized variables over to specs

References #14

utils/doclint/README.md

@@ -0,0 +1,30 @@
+# DocLint
+
+**Doclint** is a small program that lints Puppeteer's documentation against
+Puppeteer's source code.
+
+Doclint works in a few steps:
+
+1. Read sources in `lib/` folder, parse AST trees and extract public API
+2. Read sources in `docs/` folder, render markdown to HTML, use puppeteer to traverse the HTML
+  and extract described API
+3. Compare one API to another
+
+Doclint is also responsible for general markdown checks, most notably for the table of contents
+relevancy.
+
+## Running
+
+```bash
+npm run doc
+```
+
+## Tests
+
+Doclint has its own set of jasmine tests, located at `utils/doclint/test` folder.
+
+To execute tests, run:
+
+```bash
+npm run test-doclint
+```