docs: fix brew style

Library/Homebrew/style.rb

@@ -144,7 +144,7 @@ module Homebrew
       files&.map!(&:expand_path)
       if files.blank? || files == [HOMEBREW_REPOSITORY]
         files = [HOMEBREW_LIBRARY_PATH]
-      elsif files.any? { |f| f.to_s.start_with? HOMEBREW_REPOSITORY/"docs" }
+      elsif files.any? { |f| (f.to_s.start_with? HOMEBREW_REPOSITORY/"docs") || (f.basename == "docs") }
         args << "--config" << (HOMEBREW_REPOSITORY/"docs/.rubocop.yml")
       elsif files.none? { |f| f.to_s.start_with? HOMEBREW_LIBRARY_PATH }
         args << "--config" << (HOMEBREW_LIBRARY/".rubocop.yml")

docs/.rubocop.yml

@@ -2,11 +2,12 @@ inherit_from: ../Library/.rubocop.yml
 
 AllCops:
   Exclude:
-  - Gemfile
-  - ".mdl*.rb"
-  - Rakefile
-  - "_site/**/*"
-  - Manpage.md
+    - Gemfile
+    - ".mdl*.rb"
+    - Rakefile
+    - "_site/**/*"
+    - Manpage.md
+    - "vendor/**/*"
 
 # These are included in docs deliberately to show what
 # `brew create` does and what the user should replace.
@@ -21,7 +22,7 @@ FormulaAudit/Homepage:
 
 Layout/LineLength:
   Exclude:
-  - Bottles.md # The bottle block line length is long in its full form.
+    - Bottles.md # The bottle block line length is long in its full form.
 
 # Apparently Casks are allowed to have constant definitions in blocks and we document this.
 Lint/ConstantDefinitionInBlock:
@@ -30,3 +31,7 @@ Lint/ConstantDefinitionInBlock:
 # A fake regexp is deliberately documented for `inreplace` in the Formula Cookbook.
 Style/RedundantRegexpArgument:
   Enabled: false
+
+# Want to be able to display partial formulae in the docs.
+Style/TopLevelMethodDefinition:
+  Enabled: false

docs/Brew-Livecheck.md

@@ -188,7 +188,7 @@ A `strategy` block for `Git` is a bit different, as the block receives an array
 livecheck do
   url :stable
   strategy :git do |tags|
-    tags.map { |tag| tag[/^(\d{4}-\d{2}-\d{2})$/i, 1]&.gsub(/\D/, "") }.compact
+    tags.filter_map { |tag| tag[/^(\d{4}-\d{2}-\d{2})$/i, 1]&.gsub(/\D/, "") }
   end
 end
 ```

docs/External-Commands.md

@@ -73,9 +73,9 @@ module Homebrew
           Do something. Place a description here.
         EOS
         switch "-f", "--force",
-              description: "Force doing something in the command."
+               description: "Force doing something in the command."
         flag   "--file=",
-              description: "Specify a file to do something with in the command."
+               description: "Specify a file to do something with in the command."
         comma_array "--names",
                     description: "Add a list of names to the command."