Adding release cadence docs (#8893)

**What this PR does / why we need it**:
Members of our community often ask about our release cadence, so I have
documented it for easy future reference.

---------

Signed-off-by: Danny Kopping <danny.kopping@grafana.com>
Co-authored-by: J Stickler <julie.stickler@grafana.com>

docs/sources/community/getting-in-touch.md

@@ -6,6 +6,7 @@ description: Contacting the Loki Team
 
 For questions regarding Loki:
 
+- Ask a question in the `#loki` channel of our [Slack](https://slack.grafana.com/) community
 - Open source Loki users are welcome to post technical questions on the Grafana Labs Community Forums under the Grafana Loki category at [community.grafana.com](https://community.grafana.com). Please be mindful that this is a community-driven support channel moderated by Grafana Labs staff where Loki maintainers and community members answer questions when bandwidth allows. Be sure to review the [Community Guidelines](https://community.grafana.com/guidelines) before posting.
 - Users deploying Loki via [Grafana Cloud](/products/cloud/) can submit support tickets via the [Grafana.com Account Portal](/login).
 - For questions regarding Enterprise support for Loki, you can get in touch with the Grafana Labs team [here](/contact?pg=docs).

docs/sources/release-notes/_index.md

@@ -13,3 +13,5 @@ listed here by version number.
 - [V2.5 release notes]({{<relref "v2-5">}})
 - [V2.4 release notes]({{<relref "v2-4">}})
 - [V2.3 release notes]({{<relref "v2-3">}})
+
+The details about our release cadence are documented [here]({{<relref "cadence">}}).

docs/sources/release-notes/cadence.md

@@ -0,0 +1,69 @@
+---
+title: Release cadence
+description: How our release process works
+weight: 1
+---
+
+# Release cadence
+
+## Stable Releases
+
+Loki releases (this includes [Promtail](/clients/promtail), [Loki Canary](/operations/loki-canary/), etc) use the following
+naming scheme: `MAJOR`.`MINOR`.`PATCH`.
+
+- `MAJOR` (roughly once a year): these releases include large new features & possible backwards-compatibility breaks.
+- `MINOR` (roughly once a quarter): these releases include new features which generally do not break backwards-compatibility, but from time to time we might introduce _minor_ breaking changes, and we will specify these in our upgrade docs.
+- `PATCH` (roughly once or twice a month): these releases include bug & security fixes which do not break backwards-compatibility.
+
+> **NOTE:** While our naming scheme resembles [Semantic Versioning](https://semver.org/), at this time we do not strictly follow its
+guidelines to the letter. Our goal is to provide regular releases that are as stable as possible, and we take backwards-compatibility
+seriously. As with any software, always read the [release notes](/release-notes) and the [upgrade guide](/upgrading) whenever
+choosing a new version of Loki to install.
+
+New releases are based of a [weekly release](#weekly-releases) which we have vetted for stability over a number of weeks.
+
+We strongly recommend keeping up-to-date with patch releases as they are released. We post updates of new releases in the `#loki` channel
+of our [Slack community](/community/getting-in-touch).
+
+You can find all of our releases [on GitHub](https://github.com/grafana/loki/releases) and on [Docker Hub](https://hub.docker.com/r/grafana/loki).
+
+## Weekly Releases
+
+Every Monday morning, we create a new "weekly" release from the tip of the [`main` branch](https://github.com/grafana/loki).
+These releases use the following naming scheme:
+
+<ul>
+<code>weekly-k&lt;week-number&gt;</code> where <code>&lt;week-number&gt;</code> is the number of weeks since we began this process (2020-07-06).
+</ul>
+
+These weekly releases are deployed across our Grafana Cloud Logs fleet of instances. We test these releases for stability
+by deploying them through development, pre-production, and production instances.
+
+Generally these weekly releases are considered stable enough to run, but we provide zero stability guarantees and these
+releases _should not be run in production_ unless you are willing to tolerate some risk.
+
+You can find these releases on [Docker Hub](https://hub.docker.com/r/grafana/loki/tags?page=1&name=k).
+
+### Which release will my merged PR be part of?
+
+Once your PR is merged to `main`, you can expect it to become available in the next week's
+[weekly release](#weekly-releases). To find out which stable or weekly releases a commit is included in, use the following tool:
+
+`tools/which-release.sh`
+
+For example, [this PR](https://github.com/grafana/loki/pull/7472) was [merged](https://github.com/grafana/loki/pull/7472#event-8431624850)
+into the commit named `d434e80`. Using the tool above, we can see that is part of release 2.8 and several weekly releases:
+
+```bash
+$ ./tools/which-release.sh d434e80                                 
+Commit was found in the following releases:
+  release-2.8.x
+Commit was found in the following weekly builds:
+  k136
+  k137
+  k138
+  k139
+  k140
+  k141
+  k142
+```