Fix typo in Loki authentication docs (#11007)

**What this PR does / why we need it**:

Typo fix

**Which issue(s) this PR fixes**:
Fixes #<issue number>

**Special notes for your reviewer**:

**Checklist**
- [ ] Reviewed the
[`CONTRIBUTING.md`](https://github.com/grafana/loki/blob/main/CONTRIBUTING.md)
guide (**required**)
- [ ] Documentation added
- [ ] Tests updated
- [ ] `CHANGELOG.md` updated
- [ ] If the change is worth mentioning in the release notes, add
`add-to-release-notes` label
- [ ] Changes that require user attention or interaction to upgrade are
documented in `docs/sources/setup/upgrade/_index.md`
- [ ] For Helm chart changes bump the Helm chart version in
`production/helm/loki/Chart.yaml` and update
`production/helm/loki/CHANGELOG.md` and
`production/helm/loki/README.md`. [Example
PR](d10549e)
- [ ] If the change is deprecating or removing a configuration option,
update the `deprecated-config.yaml` and `deleted-config.yaml` files
respectively in the `tools/deprecated-config-checker` directory. <!--
TODO(salvacorts): Add example PR -->

docs/sources/operations/authentication.md

@@ -21,7 +21,7 @@ A list of open-source reverse proxies you can use:
 Note that when using Loki in multi-tenant mode, Loki requires the HTTP header
 `X-Scope-OrgID` to be set to a string identifying the tenant; the responsibility
 of populating this value should be handled by the authenticating reverse proxy.
-For more inforamtion, read the [multi-tenancy]({{< relref "./multi-tenancy" >}}) documentation.
+For more information, read the [multi-tenancy]({{< relref "./multi-tenancy" >}}) documentation.
 
 For information on authenticating Promtail, see the documentation for [how to
 configure Promtail]({{< relref "../send-data/promtail/configuration" >}}).