docs: provide options to refer to a group of targets (#20522)

I believe the docs would benefit from having `cli` subsystem mentioned
when explaining how to address targets. Also, the generic `target` is
not referred anywhere, but is a powerful technique to provide a proxy to
address multiple targets.

Author: AlexTereshenkov

docs/docs/using-pants/advanced-target-selection.mdx

@@ -193,3 +193,28 @@ For other goals, you can leverage shell piping to partition the input targets in
 ```bash
 pants list :: | awk 'NR % 5 == 0' | xargs pants package
 ```
+
+## Using CLI aliases
+
+If setting tags on individual targets is not feasible, there are a few other options available to refer to multiple targets.
+
+If you have an operation that you perform often on a certain group of targets, you can use the
+[cli](../../reference/subsystems/cli) subsystem options to create shortcuts. For instance, this alias
+would let you run `pants publish-libraries` to publish all Python distributions declared in the `src/libA` and `src/libB`
+directories.
+
+```toml title="pants.toml"
+[cli.alias]
+publish-libraries = "--filter-target-type=python_distribution --filter-address-regex=\"['^src/libA/,^src/libB/']\" publish src::"
+```
+
+You can use any argument or goal, and the alias doesn't need to be a "full" invocation of Pants.
+For instance, you could combine filtering arguments along with `--changed-since` flag and a tag to refer to long-running
+integration tests that have been recently modified:
+
+```toml title="pants.toml"
+[cli.alias]
+--integration-long = "--changed-since --filter-target-type=python_test --tag=long"
+```
+
+You can now invoke `pants --integration-long test tests::` to run the relevant tests.

docs/docs/using-pants/key-concepts/targets-and-build-files.mdx

@@ -166,6 +166,50 @@ You can use the prefix `!!` to transitively exclude a dependency, meaning that e
 Transitive excludes can only be used in target types that conventionally are not depended upon by other targets, such as `pex_binary`, `python_distribution`, and `python_test` / `python_tests`. This is meant to limit confusion, as using `!!` in something like a `python_source` / `python_sources` target could result in surprising behavior for everything that depends on it. (Pants will print a helpful error when using `!!` when it's not legal.)
 :::
 
+## Using the generic `target`
+
+[`target`](../../..reference/targets/target) is a generic target with no specific type.
+It can be used as a generic collection of targets to group related, but distinct targets into one single target.
+
+### Referring to a group of targets
+
+You could use the generic `target` when you need to group multiple targets to refer to them as a unit
+(a single dependency) to reduce repetition:
+
+```python title="BUILD"
+target(
+    name="python-libs",
+    dependencies=["src/python/libraries/libA", "src/python/libraries/libB"],
+)
+```
+
+If declared in the root of your workspace, you can now address the Python libraries by `//:python-libs`:
+
+```bash
+$ pants dependencies //:python-libs
+````
+
+### Creating aliases for targets
+
+If you have some targets declared in BUILD files that are stored deep within the directory structure of your workspace,
+you can make it easier to refer to that target when listing that target among dependencies of other targets.
+
+For example, you can simplify accessing a target by creating another target that will serve as an alias definition in
+a BUILD file stored in a more convenient location in the workspace, for instance, in the build root directory:
+
+```python title="BUILD"
+target(
+    name="deployment-bins",
+    dependencies=["src/golang/production/cloud/deployment/binaries:tools"]
+)
+```
+
+You can now refer to that target more concisely in BUILD files:
+
+```python title="BUILD"
+python_sources(dependencies=["//:deployment-bins"])
+```
+
 ## Field default values
 
 As mentioned above in [BUILD files](./targets-and-build-files.mdx#build-files), most target fields have sensible defaults. And it's easy to override those values on a specific target. But applying the same non-default value on many targets can get unwieldy, error-prone and hard to maintain. Enter `__defaults__`.