Generate doxygen documentation

[leodido]

What type of PR is this?

/kind documentation

/kind feature

Any specific area of the project related to this PR?

/area build

What this PR does / why we need it:

This PR introduces a way to build the Falco development docs. 🎉

Docs for developers, and people that want to contribute to Falco, are a long-standing feature needed by our community. Thus, I decided to package this gift for our awesome community 🎁

Namely, this PR:

• introduces a new target - ie., GenerateDocs - to generate Doxygen documentation
  • to work it requires doxygen, jinja2, and pygments installed on the machine
  • uses mosra/m.css (A no-nonsense, no-JavaScript CSS framework for content-oriented websites)
    • live demo of a possible final result here 👈
• introduces CPM (that I intend to use to simplify the way we handle all our dependencies)
  • it's a CMake module that adds dependency management capabilities to CMake
  • It's built as a thin wrapper around CMake's FetchContent module that adds version control, caching, a simple API
  • read more at the provided link for extensive documentation about it

How to try it out

cmake -Hdocumentation -Bbuild/docs
cmake --build build/docs --target GenerateDocs

Then open the build/docs/doxygen/html/index.html file in your browser.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Things to do to consider it 100% done:

• add doxygen comments to our source code
• fine-tune the generated docs structure (navbars, etc.)
• fine-tune the generated docs content
• publish the HTML using a CI job (to discuss with the community how/where/etc.)
  • community choose to put development docs on a new website (falcosecurity.dev)
  • obtain falcosecurity.dev

/hold

Does this PR introduce a user-facing change?:

new: Falco development docs at ...

[poiana]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[leodido]

Some screenshots of the current (not final) outcome:

[leodido]

/milestone 0.27.0

[leogr]

I love this 🤩

Really nice and clean 👍

PS
I have adjusted the license's badge link that should fix the README rendering issue.

[leodido]

Update:

thanks to the CNCF (@caniszczyk) we now have falcosecurity.dev 🥳 and we can unblock this effort

[leodido]

/milestone 0.28.1

[deepskyblue86]

Up!

[poiana]

Issues go stale after 90d of inactivity.

Mark the issue as fresh with /remove-lifecycle stale.

Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Provide feedback via https://github.com/falcosecurity/community.

/lifecycle stale

[jasondellaluce]

/milestone 0.32.0

[leogr]

Hey @leodido

What do you think about unblocking this PR so that we can continue this effort in subsequent PRs?

Even though the current status of this PR does not achieve the final result, it seems to be working. Thus, IMO, it is worth merging it as-is now.
Wdyt? 😃

[poiana]

Stale issues rot after 30d of inactivity.

Mark the issue as fresh with /remove-lifecycle rotten.

Rotten issues close after an additional 30d of inactivity.

If this issue is safe to close now please do so with /close.

Provide feedback via https://github.com/falcosecurity/community.

/lifecycle rotten

[poiana]

Rotten issues close after 30d of inactivity.

Reopen the issue with /reopen.

Mark the issue as fresh with /remove-lifecycle rotten.

Provide feedback via https://github.com/falcosecurity/community.
/close

[poiana]

@poiana: Closed this PR.

In response to this:

Rotten issues close after 30d of inactivity.

Reopen the issue with /reopen.

Mark the issue as fresh with /remove-lifecycle rotten.

Provide feedback via https://github.com/falcosecurity/community.
/close

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