Link to PRs in changelog

[doc only]

CHANGELOG.md

@@ -3,18 +3,18 @@
 [Full changelog](https://github.com/mozilla/glean/compare/v28.0.0...master)
 
 * General:
-  * The version of glean_parser has been upgraded to v1.20.2:
+  * The version of glean_parser has been upgraded to v1.20.2 ([#827](https://github.com/mozilla/glean/pull/827)):
     * **Breaking change:** glinter errors found during code generation will now return an error code.
     * `glean_parser` now produces a linter warning when `user` lifetime metrics are set to expire. See [bug 1604854](https://bugzilla.mozilla.org/show_bug.cgi?id=1604854) for additional context.
 * Android
-  * The `PingType.submit()` can now be called without a `null` by Java consumers.
+  * The `PingType.submit()` can now be called without a `null` by Java consumers ([#853](https://github.com/mozilla/glean/pull/853)).
 * Python:
-  * BUGFIX: Fixed a race condition in the `atexit` handler, that would have resulted in the message "No database found".  See [bug 1634310](https://bugzilla.mozilla.org/show_bug.cgi?id=1634310).
-  * The Glean FFI header is now parsed at build time rather than runtime. Relevant for packaging in `PyInstaller`, the wheel no longer includes `glean.h` and adds `_glean_ffi.py`.
+  * BUGFIX: Fixed a race condition in the `atexit` handler, that would have resulted in the message "No database found" ([#854](https://github.com/mozilla/glean/pull/854)).
+  * The Glean FFI header is now parsed at build time rather than runtime. Relevant for packaging in `PyInstaller`, the wheel no longer includes `glean.h` and adds `_glean_ffi.py` ([#852](https://github.com/mozilla/glean/pull/852)).
   * The minimum versions of many secondary dependencies have been lowered to make the Glean SDK compatible with more environments.
-  * Dependencies that depend on the version of Python being used are now specified using the `Declaring platform specific dependencies syntax in setuptools <https://setuptools.readthedocs.io/en/latest/setuptools.html#declaring-platform-specific-dependencies>`__. This means that more recent versions of dependencies are likely to be installed on Python 3.6 and later, and unnecessary backport libraries won't be installed on more recent Python versions.
+  * Dependencies that depend on the version of Python being used are now specified using the [Declaring platform specific dependencies syntax in setuptools](https://setuptools.readthedocs.io/en/latest/setuptools.html#declaring-platform-specific-dependencies). This means that more recent versions of dependencies are likely to be installed on Python 3.6 and later, and unnecessary backport libraries won't be installed on more recent Python versions.
 * iOS:
-  * Glean for iOS is now being built with Xcode 11.4.1
+  * Glean for iOS is now being built with Xcode 11.4.1 ([#856](https://github.com/mozilla/glean/pull/856))
 
 # v28.0.0 (2020-04-23)