Start release notes for upcoming release 0.4.0

[cameron-craig-etas]

#422

This PR adds a release notes file for the next lifecycle release. I have not added all release information yet - only some upgrade instructions for the public mocks that are changing names .

[github-actions]

License Check Results

🚀 The license check job ran with the Bazel command:

bazel run --lockfile_mode=error //:license-check

Status: ⚠️ Needs Review

Click to expand output

[License Check Output]
Extracting Bazel installation...
Starting local Bazel server (8.6.0) and connecting to it...
INFO: Invocation ID: 1a0bc934-3bf2-406c-ad82-ebeafe3240fd
Computing main repo mapping: 
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Computing main repo mapping: 
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Analyzing: target //:license-check (1 packages loaded, 0 targets configured)
Analyzing: target //:license-check (1 packages loaded, 0 targets configured)

Analyzing: target //:license-check (32 packages loaded, 10 targets configured)

Analyzing: target //:license-check (88 packages loaded, 10 targets configured)

Analyzing: target //:license-check (148 packages loaded, 585 targets configured)

Analyzing: target //:license-check (159 packages loaded, 6264 targets configured)

Analyzing: target //:license-check (164 packages loaded, 6285 targets configured)

Analyzing: target //:license-check (169 packages loaded, 6334 targets configured)

Analyzing: target //:license-check (173 packages loaded, 9567 targets configured)

Analyzing: target //:license-check (176 packages loaded, 11463 targets configured)

Analyzing: target //:license-check (177 packages loaded, 11587 targets configured)

INFO: Analyzed target //:license-check (177 packages loaded, 11589 targets configured).
INFO: Found 1 target...
Target //:license.check.license_check up-to-date:
  bazel-bin/license.check.license_check
  bazel-bin/license.check.license_check.jar
INFO: Elapsed time: 25.803s, Critical Path: 0.44s
INFO: 16 processes: 4 disk cache hit, 12 internal.
INFO: Build completed successfully, 16 total actions
INFO: Running command line: bazel-bin/license.check.license_check ./formatted.txt <args omitted>
usage: org.eclipse.dash.licenses.cli.Main [-batch <int>] [-cd <url>]
       [-confidence <int>] [-ef <url>] [-excludeSources <sources>] [-help] [-lic
       <url>] [-project <shortname>] [-repo <url>] [-review] [-summary <file>]
       [-timeout <seconds>] [-token <token>]

[github-actions]

The created documentation from the pull request is available at: docu-html