Fix typos and improve wording

docs/maintenance-upgrading-services.md

@@ -4,14 +4,14 @@ This playbook not only installs the various Matrix services for you, but can als
 
 If you want to be notified when new versions of Synapse are released, you should join the Synapse Homeowners room: [#homeowners:matrix.org](https://matrix.to/#/#homeowners:matrix.org).
 
-To upgrade the services:
+To upgrade services:
 
 - update your playbook directory (`git pull`), so you'd obtain everything new we've done
 
-- take a look at [the changelog](../CHANGELOG.md) to see if there have been any backward-incomptabile changes that you need to take care of
+- take a look at [the changelog](../CHANGELOG.md) to see if there have been any backward-incompatible changes that you need to take care of
 
 - re-run the [playbook setup](installing.md): `ansible-playbook -i inventory/hosts setup.yml --tags=setup-all`
 
 - restart the services: `ansible-playbook -i inventory/hosts setup.yml --tags=start`
 
-**Note**: major version upgrades are not done to the internal PostgreSQL database. To upgrade that one, refer to the [upgrading PostgreSQL guide](maintenance-postgres.md#upgrading-postgresql).
+**Note**: major version upgrades to the internal PostgreSQL database are not done automatically. To upgrade it, refer to the [upgrading PostgreSQL guide](maintenance-postgres.md#upgrading-postgresql).