Correct yml examples

src/ameba/rule/performance/chained_call_with_no_bang.cr

@@ -25,7 +25,7 @@ module Ameba::Rule::Performance
   # YAML configuration example:
   #
   # ```
-  # Performance/ChainedCallWithNoBang
+  # Performance/ChainedCallWithNoBang:
   #   Enabled: true
   #   CallNames:
   #     - uniq

src/ameba/rule/performance/compact_after_map.cr

@@ -16,7 +16,7 @@ module Ameba::Rule::Performance
   # YAML configuration example:
   #
   # ```
-  # Performance/CompactAfterMap
+  # Performance/CompactAfterMap:
   #   Enabled: true
   # ```
   class CompactAfterMap < Base

src/ameba/rule/performance/flatten_after_map.cr

@@ -16,7 +16,7 @@ module Ameba::Rule::Performance
   # YAML configuration example:
   #
   # ```
-  # Performance/FlattenAfterMap
+  # Performance/FlattenAfterMap:
   #   Enabled: true
   # ```
   class FlattenAfterMap < Base

src/ameba/rule/performance/map_instead_of_block.cr

@@ -19,7 +19,7 @@ module Ameba::Rule::Performance
   # YAML configuration example:
   #
   # ```
-  # Performance/MapInsteadOfBlock
+  # Performance/MapInsteadOfBlock:
   #   Enabled: true
   # ```
   class MapInsteadOfBlock < Base