404 and outdated links within guide editor

[belfie13]

a couple minor dead links i couldn't find an open issue for.

in the "Where to start?" section

the link to respec shows a warning in the readme stating
"Moved to https://github.com/speced/respec"

at the bottom of the page where it states "feedback is to @w3c/tilt"
the https://github.com/orgs/w3c/teams/tilt gets a http 404 error

[plehegar]

respec and bikeshed links fixed b83c39a

The TiLT one is trickier. It does work if you are logged in on GH. Not sure how to make it more public :(

[belfie13]

@plehegar aha i see, so i think this is good then? maybe indicate that the tilt link isnt public somehow?