CHANGELOG: add some things we missed

CHANGELOG.md

@@ -13,6 +13,9 @@ v0.23 + 1
 * You can now set your own user-agent to be sent for HTTP requests by
   using the `GIT_OPT_SET_USER_AGENT` with `git_libgit2_opts()`.
 
+* You can set custom HTTP header fields to be sent along with requests
+  by passing them in the fetch and push options.
+
 * Tree objects are now assumed to be sorted. If a tree is not
   correctly formed, it will give bad results. This is the git approach
   and cuts a significant amount of time when reading the trees.
@@ -24,12 +27,15 @@ v0.23 + 1
   the opportunity for concurrent operations and not committing any
   changes until the unlock.
 
-
 * `git_diff_options` added a new callback `progress_cb` to report on the
   progress of the diff as files are being compared. The documentation of
   the existing callback `notify_cb` was updated to reflect that it only
   gets called when new deltas are added to the diff.
 
+* `git_fetch_options` and `git_push_options` have gained a `custom_headers`
+  field to set the extra HTTP header fields to send.
+
+
 * `git_stream_register_tls()` lets you register a callback to be used
   as the constructor for a TLS stream instead of the libgit2 built-in
   one.
@@ -65,6 +71,10 @@ v0.23 + 1
 * The `notify_payload` field of `git_diff_options` was renamed to `payload`
   to reflect that it's also the payload for the new progress callback.
 
+* The `git_config_level_t` enum has gained a higher-priority value
+  `GIT_CONFIG_LEVEL_PROGRAMDATA` which represent a rough Windows equivalent
+  to the system level configuration.
+
 v0.23
 ------