Update changelog for v1.2

Signed-off-by: Peter Grayson <[email protected]>

Author: jpgrayson

CHANGELOG.md

@@ -1,9 +1,15 @@
 # Changelog
 
-## [Unreleased]
+## [1.2] 2021-09-26
 
 ### Removed
 
+### Deprecated
+- Python 3.5, which became EOL 2020-09-13, support is deprecated and
+  will be removed in a future StGit release
+- Python 3.6, which will be EOL 2021-12-23, support is deprecated and
+  will be removed in a future StGit release
+
 ### Added
 - `stg rebase ` learns `--interactive`; easily re-order, edit, squash,
   fixup, or delete patches via your editor
@@ -18,8 +24,17 @@
 - `stg push` and `stg float` learn `--noapply` option; allows patches
   to be reordered without updating worktree and deferring merge conflict
   resolution (#144)
+- `stg edit`, `stg refresh`, and `stg new` learn the `--sign-by`,
+  `--ack-by`, and `--review-by` options which allow those respective
+  trailers' values to be specified by the user on the command line (#92)
 
 ### Changed
+- Stack metadata version 5; stack metadata is moved from
+  `refs/heads/<branch>.stgit` to `refs/stacks/<branch>` and the stack
+  metadata file now uses a JSON format instead of the prior custom
+  format; the stack metadata will be upgraded to v5 on first use of
+  this version of StGit; like all stack metadata upgrades, **this is a
+  one-way auto-upgrade for existing stacks** (#65)
 - Use setuptools instead of distutils for packaging
 - No git or python version checks in setup.py
 - Use different dynamic versioning system
@@ -28,6 +43,17 @@
 - The editor window text for `stg squash` has been modified to mirror
   git's behavior -- the squash edit message now includes all commits
   (#71)
+- Binary diffs are no longer shown when with `stg edit -d`
+- Multiple trailers can now be added at once; this is now allowed, for
+  example: `stg edit --sign --review --ack`
+- Update zsh completion for `stg rebase` to show local and remote heads
+  (#102)
+- Zsh completions for commands with patch arguments now comprehend the
+  effect of `-b/--branch` and `-B/--ref-branch`
+- Zsh completions now guard patch names--one less TAB press to complete
+  patch names in certain contexts
+- `stg import` now extracts the `Message-ID` email header into the patch
+  message (#42)
 
 ### Fixed
 - Repair crash when attempting to export empty patch (#112)
@@ -38,12 +64,15 @@
 - Workaround child process reaping race on Windows (#78)
 - Repair crash with `stg float --series` when bad patch name in series
 - Repair zsh completion for `stg float` to accept multiple patch names
+- Repair zsh completion for changed files, affecting `stg refresh` and
+  `stg diff`
 
 ### Internal
 - Add link to coverage.io project to CONTRIBUTING.md
 - Set smart `exclude_lines` default for 'coverage'
 - Expanded test suite for `stg edit`
 - Add pkgtest.py script to help test StGit packaging
+- Cleanup .gitignore files
 
 
 ## [1.1] 2021-04-30