Add explanations about different approaches to configure app, plugins & modules

[Tschakki]

Description

Align the documentation to

• describe the recommended way how to configure plugins and modules
• describe the alternative ways to configure.
• ExplanationWhich values in the config cannot be changed without doing a hard fork and why? Which options are safe to change by the node operator?
• Maybe discuss advantages and disadvantages of the different approaches.
• Disadvantages of very large block time (finality) could be discussed in the config guide (info box)

Motivation

Inform devs of different configuration approaches and best practices.

Additional information

Should be added in advanced explanations or dev guides.

Wether to put the value in genesis config or in the code is basically choice of flexibility. if you want some value to be flexible, it should be in genesis config but otherwise as constant. for example, you are creating a module and providing to everyone, if you want a value to be configruable on each chain, it should be genesis config. Otherwise, just a constant in the code