first solid draft of the SPDX CryptAlg release process

[toscalix]

The release policy has been maturing in the ticket #52 . It is not finalise but, since it is a long document, we would like to incorporate it in two steps.

There are some sections that will require, to be developed, that the List goes through a first release, in order to describe the mechanics in this policy. Those sections are marked in the ToC of the document. Guidelines about which content should those sections incorporate has been added to each of these sections.

The rest of the sections has been developed already and they are ready for review.

[toscalix]

The second commit brings:
* Key terms: deprecation and generation removed from key terms (14.1)
* Sections 12.4 and 13.3 adapted to soften the requirement to open an issue before a PR. In trivial cases we should go directly to PRs
* Moved RELEASE-HISTORY.md and CHANGELOG.md from the Key Terms to the Reference section
* Added links to every entry in the 14.2 section
* Some minor changes in the Key Terms (14.1) section