[v10.0.x] Docs: adds docs on excluding labels (#78887)

Docs: adds docs on excluding labels (#78806)

* Docs: adds docs on excluding labels

* run prettier

* Update docs/sources/alerting/fundamentals/annotation-label/labels-and-label-matchers.md

Co-authored-by: Gilles De Mey <gilles.de.mey@gmail.com>

* adds table for display

* ran prettier

---------

Co-authored-by: Gilles De Mey <gilles.de.mey@gmail.com>
(cherry picked from commit 1b2a621533)

Co-authored-by: brendamuir <100768211+brendamuir@users.noreply.github.com>

docs/sources/alerting/fundamentals/annotation-label/labels-and-label-matchers.md

@@ -50,3 +50,15 @@ then:
 - A label matcher defined as `id=~[0-9]+` matches this alert rule.
 - A label matcher defined as `baz!~[0-9]+` matches this alert rule.
 - Two label matchers defined as `foo=bar` and `id=~[0-9]+` match this alert rule.
+
+## Exclude labels
+
+You can also write label matchers to exclude labels.
+
+Here is an example that shows how to exclude the label `Team`. You can choose between any of the values below to exclude labels.
+
+| Label  | Operator | Value |
+| ------ | -------- | ----- |
+| `team` | `=`      | `""`  |
+| `team` | `!~`     | `.+`  |
+| `team` | `=~`     | `^$`  |