docs(debug): Improve Go debugging documentation

[halvards]

Update explanation of how Go debugging works in Skaffold and add explanations for ko builder users.

Also update links to the VS Code Go extension.

Related: #6843
Tracking: #6041

[codecov]

Codecov Report

Merging #6852 (a88ab2f) into main (290280e) will decrease coverage by 1.33%.
The diff coverage is 61.83%.

@@            Coverage Diff             @@
##             main    #6852      +/-   ##
==========================================
- Coverage   70.48%   69.15%   -1.34%     
==========================================
  Files         515      547      +32     
  Lines       23150    25064    +1914     
==========================================
+ Hits        16317    17332    +1015     
- Misses       5776     6570     +794     
- Partials     1057     1162     +105     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/deploy.go	52.00% <ø> (-1.85%)	⬇️
cmd/skaffold/app/cmd/dev.go	84.61% <0.00%> (ø)
cmd/skaffold/app/cmd/flags.go	91.00% <0.00%> (+0.18%)	⬆️
cmd/skaffold/app/cmd/render.go	36.66% <0.00%> (-4.72%)	⬇️
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/fix.go	68.85% <40.00%> (-7.62%)	⬇️
cmd/skaffold/app/cmd/lint.go	42.85% <42.85%> (ø)
cmd/skaffold/app/cmd/find_configs.go	48.88% <50.00%> (+0.24%)	⬆️
cmd/skaffold/app/skaffold.go	76.19% <70.00%> (-8.43%)	⬇️
... and 162 more

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