Add parentheses to method links in online class reference

[tetrapod00]

Closes godotengine/godot-docs#10641.

Currently we use parentheses when linking to methods within the editor class reference, but not the online class reference. This PR unifies the look of both by using parentheses for method links in the online class reference.
Editor:

Online, master:

Online, after this PR:

Testing:

• Generate the RST files with some variant of the command from the Sync Class Reference GHA (https://github.com/godotengine/godot-docs/blob/cb0009a3c89c5841e8644e9c6f6a95d96821d941/.github/workflows/sync_class_ref.yml#L59). I used this on Windows:

.\doc\tools\make_rst.py --color -o ../classes -l en ./doc/classes ./modules ./platform

• Clone the docs repo if you don't have it. Copy the generated classes to the classes folder of the docs repo, overwriting existing files. I did this by hand 🙂
• Build the manual.

[Calinou]

Looks good to me.

In the long run, I wonder if methods that accept at least one parameter (even if optional) should be denoted as something(...) instead, like we do in the script editor autocompletion tooltip since 4.4. We'd need to carry this change both in the editor help and class reference generation though, and it's better discussed in its own proposal.

[tetrapod00]

We'd need to carry this change both in the editor help and class reference generation though, and it's better discussed in its own proposal.

If we want to keep everything lined up, we would also want to update the manual and its guidelines too, which requires a good bit more manual work.

[Repiteo]

Lining up everything would likely require some unification of the online/editor sources, which is a mammoth of a bridge to cross when we come to it

This isolated change is harmless at worst & helps readability on top of unifying the styles; let's ship it!

[Repiteo]

Thanks!