docs: Resolve typos in release notes

Signed-off-by: Stephen Finucane <stephen@that.guru>

Author: stephenfin

releasenotes/notes/prelude-2_1-9fb70d76c5c835d4.yaml

@@ -6,14 +6,14 @@ prelude: |
     and so isn't suitable for a stable backport. Event listing in the API
     has also been sped up by refactoring the queries.
 
-    This release also includes the feature development that had accured in
-    the mean time, and numerous bug fixes.
+    This release also includes the feature development that had accrued in
+    the mean time and numerous bug fixes.
 
     The REST API version has been bumped to 1.1.
 issues:
   - Series parsing in the presence of parallel mail processing is still
     unreliable.
-  - Several more minor issues can be browsed on our `issue tracker 
+  - Several more minor issues can be browsed on our `issue tracker
     <https://github.com/getpatchwork/patchwork/issues>`_.
 fixes:
   - A nasty race condition bug that could cause patches in a series to be