Document how to cycle colors

[KronosTheLate]

This PR adds a skeleton for a sentence I am missing before i can make use of ColorCycle, where i am hoping that someone who knows the answer can correct the part in all caps. Alternativly, linking to some documentation would be great.

[rolandlo]

It's <Alt>+c according to the code:
https://github.com/xournalpp/xournalpp/blob/2809cb4fd1ce20723be688421f54223602ed22bf/plugins/ColorCycle/main.lua#L3
You can use any other accelerator by changing that line. As for documentation, this section on the website is relevant.

[KronosTheLate]

That is an excellent answer, and I have NO idea where i could easily find that information other than looking up the structure of the Lua files for a general purpose, which I am not interested in. Thanks for the reply ^_^

Should a general recipe like you outlined (inspecting the .lua file) be included at the top of the section?

[rolandlo]

In general before executing any scripts/plugins it is highly recommended to take a look what it does. For two reasons:

1. security (a hacker could have modified the script/plugin in a way that it executes malware)
2. you may want to make some modifications, so that it satisfies your needs. This is easy for a Lua plugin (where you can just adjust a line or a couple of lines and don't need to compile anything) in comparison with the C++ codebase (where you first need to setup the whole system so you can compile the project and then you have to find one or more of hundreds of source files, where you need to make changes)

Maybe we should add a comment in that direction to the website.