Fix #10778 Dev guide, JSDoc and migration documentation for the new homepage plugins

[allyoucanmap]

Description

This PR includes JSDoc and migration guidelines for the new hompage plugins.
It includes also a script to update the docma-config.json for msApi and plugins sections, new command added to package.json is:

npm run jsdoc:update

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Developer Guide

Issue

What is the current behavior?

#10778

What is the new behavior?

JSDoc and migration guidelines for the new hompage plugins

Breaking change

Does this PR introduce a breaking change? (check one with "x", remove the other)

• No

Other useful information

[tdipisa]

@allyoucanmap great job! In my opinion it would be good to have a kind of validator at build time to check if the docma-config file is updated throwing a warning if necessary by making the app build to fail. This way we can be aware over time if something is missing.

[allyoucanmap]

@tdipisa I included a new npm run jsdoc:check that runs just before the jsdoc build (cde6ab0)