Add examples and update the documentation to the wp post term (#398)

* add more examples to the `wp post term` command

* update CommandWithTerms docs

* fix typo

* update from slug to name

* remove `(space-separated)`

Author: Rahmon

src/Post_Term_Command.php

@@ -8,9 +8,27 @@
  *
  * ## EXAMPLES
  *
- *     # Set post terms
+ *     # Set category post term `test` to the post ID 123
  *     $ wp post term set 123 test category
+ *     Success: Set term.
+ *
+ *     # Set category post terms `test` and `apple` to the post ID 123
+ *     $ wp post term set 123 test apple category
  *     Success: Set terms.
+ *
+ *     # List category post terms for the post ID 123
+ *     $ wp post term list 123 category --fields=term_id,slug
+ *     +---------+-------+
+ *     | term_id | slug  |
+ *     +---------+-------+
+ *     | 2       | apple |
+ *     | 3       | test  |
+ *     +----------+------+
+ *
+ *     # Remove category post terms `test` and `apple` for the post ID 123
+ *     $ wp post term remove 123 category test apple
+ *     Success: Removed terms.
+ *
  */
 class Post_Term_Command extends CommandWithTerms {
 	protected $obj_type = 'post';

src/WP_CLI/CommandWithTerms.php

@@ -121,11 +121,12 @@ public function list_( $args, $assoc_args ) {
 	 * : The name of the term's taxonomy.
 	 *
 	 * [<term>...]
-	 * : The name of the term or terms to be removed from the object.
+	 * : The slug of the term or terms to be removed from the object.
 	 *
 	 * [--by=<field>]
 	 * : Explicitly handle the term value as a slug or id.
 	 * ---
+	 * default: slug
 	 * options:
 	 *   - slug
 	 *   - id
@@ -216,6 +217,7 @@ public function remove( $args, $assoc_args ) {
 	 * [--by=<field>]
 	 * : Explicitly handle the term value as a slug or id.
 	 * ---
+	 * default: slug
 	 * options:
 	 *   - slug
 	 *   - id
@@ -261,6 +263,7 @@ public function add( $args, $assoc_args ) {
 	 * [--by=<field>]
 	 * : Explicitly handle the term value as a slug or id.
 	 * ---
+	 * default: slug
 	 * options:
 	 *   - slug
 	 *   - id