Release notes: Add instructions for generating commits.

Bug: N/A
Change-Id: Id8f41dedaa04e93ed149883621903cf58760d79d
AX-Relnotes: N/A
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2826275
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: Meredith Lane <meredithl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#873358}

docs/accessibility/relnotes.md

@@ -23,7 +23,8 @@ and bugs our team works on, and are utilized by multiple testing teams.
 Release notes are a collaborative effort and usually involve two or three team
 members who own the process. The process is as follows:
 1. One owner generates a list of commits for the release and pastes the output
-in a shared Google Document.
+in a shared Google Document. For more details on how to generate this list, see
+the how-to section below.
 2. The commits are split evenly among the owners.
 3. Each owner parses their assigned commits, removing irrelevant information,
 summarizing important content, contacting developers for clarification, and
@@ -33,6 +34,55 @@ release notes to the team's PgMs.
 5. The PgMs take a final pass over the document, then forward it to relevant
 stakeholders.
 
+## How to generate a list of accessibility-related commits
+There are a few prerequisites needed before you can generate a list of
+accessibility-related commits. Run the following commands:
+
+```
+$ gcert # login with your ldap and password.
+$ git clone "sso://team/chrome-a11y-core/release-notes"
+$ cd release-notes
+$ pip3 install -t lib/ -r requirements.txt
+```
+
+Now that you've cloned the repository and installed requirements, there is one
+final step needed before you can generate commits. The team-milestone-stats
+script relies on a json file that isn't committed to the repository for security
+reasons. Please follow the below steps to add the json file:
+
+1. Create a new file named 'chrome-accessibility-749c56b5a435.json' in the same
+directory as the team-milestone-stats script; leave this open for editing.
+2. In a browser, visit valentine.corp.google.com
+3. Search for "Chrome release notes json key"
+4. Copy the secret to your clipboard using the 'copy to clipboard' button
+5. Paste the secret into the new json file. Then save and close the file.
+
+Please reach out to akihiroota@, meredithl@, or chrishall@ if you run into
+any problems during this process. Note: Please do not share this file with
+anyone outside of Google.
+
+At this point, you can generate a list of commits with a single command:
+
+```
+$ python3 team-milestone-stats.py <path-to-chromium-src> <target-milestone> --html --file
+```
+
+The above command will run a script to generate a list of accessibility-related
+commits for the specified milestons. The '--html' parameter specifies that we
+want to generate an HTML file, and the '--file' parameter specifies that we want
+to save the generated output into a file, as opposed to standard terminal
+output.
+
+To get the contents of the file into a Google Doc:
+1. Go to docs.google.com
+2. Select the file picker, which should have a tooltip with the title 'Open file
+picker'.
+3. Navigate to the 'Upload' tab.
+4. Upload the html file that was generated by the script.
+
+At this point, you should be all set. Please see bullet #2 in the
+'Release Notes Process' section for further instructions.
+
 ## Why AX-Relnotes
 We require our developers to include an AX-Relnotes field in their commit
 messages to make the release notes process more distributed and accurate.