Override style-guide citation links and references

[fangism]

Summary

Currently, style guide citation links are hard-coded into the rule implementations themselves.
In the future, users and rule-set maintainers may wish to redirect these to point to their own style guides.

Proposal

Have a way at run-time to re-map each rule's citation to a new link, for example loading such a map through a command-line option that reads an external configuration.

[fangism]

b/169867142

[pawelsag]

I'm thinking about loading the custom style guide citation from the JSON file. What do you think about this idea?

[mithro]

I would suggest that we follow whatever other tools do in this area? What do clang-format and pylint do?

[pawelsag]

Most of the tools are using just plain text configuration in a format

key1: value
key2: value

I will do the same for our config:

rule 1: style guide citation 1
rule 2: style guide citation 2