docs: clarify username/password auth methods

Signed-off-by: Kwangjin Ko <kyet@me.com>

Author: 1saac-k

packages/git-proxy-cli/index.ts

@@ -604,7 +604,7 @@ yargs(hideBin(process.argv)) // eslint-disable-line @typescript-eslint/no-unused
   })
   .command({
     command: 'create-user',
-    describe: 'Create a new user',
+    describe: 'Create a new local database user',
     builder: {
       username: {
         describe: 'Username for the new user',

website/docs/quickstart/approve.mdx

@@ -106,6 +106,8 @@ $ npx -- @finos/git-proxy-cli login --username admin --password admin
 Login "admin" <admin@place.com> (admin): OK
 ```
 
+The CLI `create-user` command provisions users in GitProxy's local database only. It does not create users in external identity providers.
+
 #### 3. Approve the push with `ID`
 
 Use the commit `ID` to approve your push with the CLI: