docs: clarify docker context use affects all terminal sessions

docs/reference/commandline/context_use.md

@@ -1,13 +1,50 @@
 # context use
 
-<!---MARKER_GEN_START-->
-Set the current docker context
+Set the default context for the Docker CLI.
 
+## Usage
 
-<!---MARKER_GEN_END-->
+    docker context use CONTEXT
 
 ## Description
 
-Set the default context to use, when `DOCKER_HOST`, `DOCKER_CONTEXT` environment
-variables and `--host`, `--context` global options aren't set.
-To disable usage of contexts, you can use the special `default` context.
+`docker context use` sets the **default context** for the Docker CLI.
+
+This command updates the Docker CLI configuration (the `currentContext` field in the client configuration file, typically `~/.docker/config.json`). Because it's a configuration change, it is **sticky** and affects **all terminal sessions** that use the same Docker CLI config directory.
+
+To change the context only for a single command, or only for your current shell session, use `--context` or the `DOCKER_CONTEXT` environment variable instead.
+
+## Examples
+
+### Set the default (sticky) context
+
+This updates the CLI configuration and applies to new terminal sessions:
+
+    $ docker context use chocolate
+    chocolate
+
+    $ docker context show
+    chocolate
+
+### Use a context for a single command
+
+Use the global `--context` flag to avoid changing the default:
+
+    $ docker --context chocolate ps
+
+### Use a context for the current shell session
+
+Set `DOCKER_CONTEXT` to override the configured default in the current shell:
+
+    $ export DOCKER_CONTEXT=chocolate
+    $ docker context show
+    chocolate
+
+To stop overriding:
+
+    $ unset DOCKER_CONTEXT
+
+### Switch back to the default context
+
+    $ docker context use default
+    default