Split vocabulary.md into two documents

[fdegir]

This PR aims to start conversation around how the vocabulary.md document could be split to two for ease of read as well as for publishing on CDF Best Practices site.

Here is the update

• vocabulary.md: A note is included in the document to point people to the right document so they can still find what they are looking for.
• tools-terminology.md: Terms used by CI/CD tools are included in this document and could perhaps be considered to be published on CDF Best Practices site's technology related pages.
• pipelines-terminology.md: Terms used for common pipeline stages and steps are included in this document and could perhaps be considered to be published on corresponding places on CDF Best Practices site.

[fdegir]

Thanks all for the reviews!