Document the new Release process

[fuzzypixelz]

Describe the release item

Following changes in #10 and #41, the Release process for eclipse-zenoh has been significantly altered. Thus some elements of documentation are needed; the following items are ordered from highest to lowest priority:

1. A high-level description of the Release process is needed (oriented towards those who kick-off the release)
2. Documentation for the various actions and re-usable workflows should be provided so they can be more easily consumed by users
3. Documentation of the TypeScript modules under src
4. Documentation of the development process of eclipse-zenoh/ci itself

It is not clear if (1-4) would fit in the README without making it unreadable. Otherwise, a dedicated doc tree of Markdown files is the way to go.