chore(docs): add custom directive to dynamically generate release notes

[brettlangdon]

This new .. ddtrace-release-notes:: directive will dynamically search for all
release branches + earliest release version and generate the desired release notes

[brettlangdon]

https://1046610-61572326-gh.circle-artifacts.com/0/tmp/docs/release_notes.html

[Kyle-Verhoog]

Just a few nits, otherwise lgtm

[brettlangdon]

This PR still doesn't solve is, adding the unreleased notes from the current branch so we can validate spell checking on them, or so we can see what is unreleased on 1.x.

As well, one side effect of this PR, any branch that has this directive will always build from all release branches. Meaning when we release a bugfix release it will include release notes for all new major/minor versions that have been released.

For example:

We release 0.70.0, 0.71.0, and then 0.70.1

When we build the docs for 0.70.1 this change will also include 0.71.0's release notes instead of only being for <= 0.70.x.

We can probably get around this by checking if the current commit is for a release tag and then limiting to only that minor version as a max.

And checking for this could also help us with the spell checking on PR as well, if we notice the current commit is not for a specific release tag (and we are not on a release branch), then we can build the current branches release notes as well.... we just have to maybe get creative in how we know which release notes are unreleased/not in a release branch (reno has trouble with this as-is).

[brettlangdon]

@Mergifyio backport 0.x

[mergify]

backport 0.x

🟠 Waiting for conditions to match

• merged [:pushpin: backport requirement]

[codecov-commenter]

Codecov Report

Merging #3368 (3238928) into 1.x (9dab78a) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              1.x    #3368   +/-   ##
=======================================
  Coverage   79.46%   79.46%           
=======================================
  Files         615      615           
  Lines       46427    46427           
=======================================
  Hits        36895    36895           
  Misses       9532     9532           

---

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[brettlangdon]

I have updated this PR to address the issue of always generating ALL the notes.

Now we will look for the max version we should report for by traversing the git log until we find the first ref for a release branch or dev branch. We will then use that to determine the max version to generate for.

For example, for this branch it will find 1.x, so we set the max cutoff version to 2.0.0. If we generate from 0.60 it'll find 0.60 and set the max cutoff version to 0.61.0.

This will ensure that when we generate notes for older versions we don't include newer version in the log.

[Kyle-Verhoog]

Just a couple nits, otherwise lgtm

[brettlangdon]

@Mergifyio backport 1.0 0.60 0.59

[mergify]

backport 1.0 0.60 0.59

🟠 Waiting for conditions to match

• merged [:pushpin: backport requirement]

[brettlangdon]

Example generated from this PR: https://output.circle-artifacts.com/output/job/b31402fc-bc7c-4d37-864a-8718b5904dc2/artifacts/0/tmp/docs/release_notes.html

[mergify]

backport 1.0 0.60 0.59

✅ Backports have been created

• #3474 chore(docs): add custom directive to dynamically generate release notes (backport #3368) has been created for branch 1.0
• #3475 chore(docs): add custom directive to dynamically generate release notes (backport #3368) has been created for branch 0.60
• #3476 chore(docs): add custom directive to dynamically generate release notes (backport #3368) has been created for branch 0.59

[mergify]

backport 0.x

✅ Backports have been created

• #3477 chore(docs): add custom directive to dynamically generate release notes (backport #3368) has been created for branch 0.x

[brettlangdon]

Example from the 1.x branch build: https://output.circle-artifacts.com/output/job/86b73279-8aa7-46a0-b16a-efc58b91c708/artifacts/0/tmp/docs/release_notes.html