Update outdated links and fix syntax error
Update outdated links and fix syntax error

Re-apply the syntax error that was fixed in https://github.com/gruntjs/grunt-contrib-qunit/pull/172.
At the time, I applied it to the readme.md artefact rather than the source file, so it got reverted
in commit 8a2e4563013b00640feed684bf4e38814c2928ee.

Also:
* Update puppeteer link to v5 (the v1 manual unfortunately is no longer served).
* Change seed and noGlobals links to their specific sections.
gruntjs/grunt-contrib-qunit,gruntjs/grunt-contrib-qunit