Add hiddenPage mode

[icy-comet]

What does this PR change? What problem does it solve?
Completes and closes #712.

Changes from previous PR:

• fixed the terms layout
• tweaked the link render hook to only include the relevant rel(s) on a hiddenPage
• changed robots.txt layout to add a Disallow directive for every hiddenPage and its resources

Was the change discussed in an issue or in the Discussions before?
#712

PR Checklist

• This change adds/updates translations and I have used the template present here.
• I have enabled maintainer edits for this PR.
• I have verified that the code works as described/as intended.
• This change adds a Social Icon which has a permissive license to use it.
• This change does not include any CDN resources/links.
• This change does not include any unrelated scripts such as bash and python scripts.
• This change updates the overridden internal templates from HUGO's repository.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[RoneoOrg]

Hi @icy-comet and thanks for tackling this issue,

I've been working on it in this dedicated PR, that's fine you work on your side (and hiddenPage is a nice name!), but note that it creates duplicated code and notes, and this makes things harder to review.

Anyway, here are my suggestions:

• remove unrelated modifications from your PR. See here
• add this new feature to the documentation
• review the whole todo list and publish an updated one, this may help this PR to be improved and merged

[RoneoOrg]

Any update on this @icy-comet ?

The main branch of Papermod is still getting updates, so the delta between Papermod and this branch is getting wider and wider, making harder and harder to maintain such a PR..

Note that you submitted a new PR heavily based on a PR I previously submitted (See ^), adding lots of noise over an already complicated piece of code. I kindly reviewed your proposal, added some notes, and politely waited, and now the burden is heavier.

So.. do you want (and have the possibility to) to tackle this issue until it's merged?

[icy-comet]

hi @RoneoOrg. It's not possible for me to work on this now.

I think the PR was already complete though. Hope you see its merging through.