[irods/irods#6286] Updated REPF documentation (4-2-stable)

[korydraughn]

Cherry-picked from #200.

Updated REP links to point to 4-2-stable.

I think everything else is identical to main, but I'll do one last pass to make sure everything still applies.

[korydraughn]

Everything is correct.

However, the REPF docs do not explain what happens when a call fails before reaching the RULE_ENGINE_CONTINUE code.

I'm going to add a statement to the code example that makes it clear. I'll port it to main once merged.

[trel]

Sounds good. Good catch.

[trel]

looks good, squash

[korydraughn]

Squashed.

I think it's ready for pounds. Opening PR for main with latest tweak to code example.

[trel]

confirmed - please # all

[korydraughn]

Added #'s