fix typos

Signed-off-by: Reuben Miller <reuben.d.miller@gmail.com>

GOVERNANCE.md

@@ -282,7 +282,7 @@ minor release workflow:
 
 * The release maintainer submits a pull request to the release branch with the
  following changes:
- * `CHANEGLOG.md` entries for the patch level release
+ * `CHANGELOG.md` entries for the patch level release
  * Updates of the version numbers for all crates in the "patch"-level position,
  e.g. "0.42.0" becomes "0.42.1",
 * Once the aforementioned pull request is merged, the release maintainer
@@ -311,7 +311,7 @@ branch.
 Version number bumps happen right _after_ branchoff for a release. Doing the
 version number bump before the release would mean that the release maintainers
 would have to wait for the version-bump-pull-request, which is not acceptable
-under the preassumption that every commit from `main` can potentially be
+under the presumption that every commit from `main` can potentially be
 released.
 By bumping the numbers right _after_ the release, but for the next release, we
 automatically get a peace-of-mind state for that next release, where the release