docs: Add version menu label

[maggieneterval]

Related: #7910

Description

Adds a version menu label of "Versions" to the versions dropdown on the v2 docs site. (This is the same versions label used by https://kubernetes.io/).

User facing changes

Previously, the versions dropdown was an unlabelled chevron and had low discoverability. Now, the versions dropdown is labeled and easily discoverable.

Before:

After:

Follow-up Work

Add informational banners to v1 and v2 docs sites. See #7910 for details.

[maggieneterval]

@aaron-prindle PTAL. Thank you!

[codecov]

Codecov Report

Merging #7917 (d6ebd87) into main (290280e) will decrease coverage by 3.73%.
The diff coverage is 53.94%.

@@            Coverage Diff             @@
##             main    #7917      +/-   ##
==========================================
- Coverage   70.48%   66.75%   -3.74%     
==========================================
  Files         515      593      +78     
  Lines       23150    28703    +5553     
==========================================
+ Hits        16317    19160    +2843     
- Misses       5776     8133    +2357     
- Partials     1057     1410     +353     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/credits/export.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/deploy.go	40.90% <0.00%> (-12.94%)	⬇️
cmd/skaffold/app/cmd/test.go	44.44% <0.00%> (ø)
cmd/skaffold/skaffold.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/inspect_tests.go	62.50% <14.28%> (-1.14%)	⬇️
cmd/skaffold/app/cmd/render.go	35.48% <18.18%> (-5.90%)	⬇️
cmd/skaffold/app/cmd/lsp.go	28.12% <28.12%> (ø)
cmd/skaffold/app/cmd/run.go	64.28% <33.33%> (-9.63%)	⬇️
cmd/skaffold/app/cmd/fix.go	56.41% <37.50%> (-20.07%)	⬇️
cmd/skaffold/app/cmd/verify.go	41.17% <41.17%> (ø)
... and 364 more

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[aaron-prindle]

LGTM! This looks way better now, thanks @maggieneterval!

[tejal29]

the signing bot is acting weird here.