Whitespace adjustments in index-list.html and index.html

[waldyrious]

• Indent HTML and add line breaks to make the structure more evident (this also helps code editors identify the structure and perform e.g. collapsing of large containers)
• Remove unnecessary blank lines
• Nest script at the end of index.html's body tag rather than outside of it
• Remove unnecessary blank lines
• Use single space after commas in index-list.html Note: the two-spaces list format was first introduced (without explanation) in commit 6c29e8758e. (At the time, the helpers/generate-index-list-html.js file was called lib/create-catalog.js.)

[b-g]

@waldyrious Many thanks for this! Could you resolve the conflicts which have been introduced merging mega PR #422? Happy to merge afterwards. Cheers!

[waldyrious]

Hey @b-g, I've rebased the branch. I checked the old and the new diffs in whitespace-insensitive mode and they seem to be equivalent, so I suppose the changes should be ready to merge :) apologies for the mess — this kind of formatting changes is quite prone to conflict indeed.

[b-g]

@waldyrious Many thanks! Merged.