Minor fixes (#25059)

1) Examples: Remove double space between "option:" and "value"
2) Documentation: Fix rendering usses
3) Documentation: Remove `required: true` to match argspec

lib/ansible/modules/network/cloudengine/ce_facts.py

@@ -72,12 +72,12 @@ EXAMPLES = """
 
   - name: "Collect only the config facts"
     ce_facts:
-      gather_subset:  config
+      gather_subset: config
       provider: "{{ cli }}"
 
   - name: "Do not collect hardware facts"
     ce_facts:
-      gather_subset:  "!hardware"
+      gather_subset: "!hardware"
       provider: "{{ cli }}"
 """