fix: register hljs plaintext language

[alexiscolin]

This PR aims to fix the md rendering issue when plaintext is summon by marked.js / hljs. It just registers the plaintext module into hljs js lib.

Fixes: #2084

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 47.02%. Comparing base (f6e7dcc) to head (d7ceced).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2103   +/-   ##
=======================================
  Coverage   47.02%   47.02%           
=======================================
  Files         578      578           
  Lines       77571    77571           
=======================================
  Hits        36477    36477           
  Misses      38059    38059           
  Partials     3035     3035           

Flag	Coverage Δ
gno.land	61.68% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[thehowl]

where does this new highlight file come from?

it doesn't seem to match what I get when using the download page with go and plaintext...

[alexiscolin]

@thehowl (and json), I customized it myself but do you prefer this one? :)

[thehowl]

I don't have strong preferences either way BTW; it's just that minified code is never nice to review, and as a matter of principle, I think minified code should be either:

1. generated from un-minified versions (and perhaps, have the minified version gitignore'd)
2. easily retrievable from a common, trusted source (like in this case)

otherwise, we're vulnerable to an attack by injecting malicious code into minified code (which we don't review as accurately). Not saying you are, but it is a matter of principle

[thehowl]

matches what I'd expect, LGTM

[alexiscolin]

@thehowl I agree, I would love to have/bring some basic front-end tasks pipelining to minify styles and scripts (automatically on CI for example). Now it's a real burden to work on it (and to test it)... Maybe something we could discuss about while we revamp gnoweb UX and front next weeks?