Feature/line selections

[EvieePy]

Description

Adds line selections/highlighting.
Clicking on a line in a file will select the line.
Clicking or Shift + Clicking and then Shift + Clicking will select the block.
This is additive when selecting downwards; E.g. it will add to the current block.

Lines can be selected via the URL with the following syntax via query string:
?lines=F[N]-L[N]-L[N]_F[N]-L[N]...

E.g. F1-L10-L15 or F2-L9

Where F[N] is the file number (1 indexed).
And the first L[N] is the starting Line followed by the ending line if there is one.

• Fixed a bug in the discord token scanner.
• Fixed some CSS.

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
  • I have updated the changelog with a quick recap of my changes.
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)
• I have read and agree to the Developer Certificate of Origin for this contribution

[AbstractUmbra]

LGTM!