MM: readme title independent of module name

Add a new flag to set this thing manually.  Will add some docs in
a future commit to explain what each of these title flags do to the UI.

CHANGELOG.md

@@ -6,8 +6,8 @@
 
 ##### Enhancements
 
-* Add `--docset-title` to set the title of a docset separately
-  to the module name.  
+* Add `--readme-title` and `--docset-title` to set the titles of the readme
+  docs page and the Dash docset independently of the module name.  
   [John Fairhurst](https://github.com/johnfairh)
 
 * Support Swift 5.9 symbolgraph extension symbols.  

lib/jazzy/config.rb

@@ -301,6 +301,10 @@ def hide_objc?
       description: 'The path to a markdown README file',
       parse: ->(rp) { expand_path(rp) }
 
+    config_attr :readme_title,
+      command_line: '--readme-title TITLE',
+      description: 'The title for the README in the generated documentation'
+
     config_attr :documentation_glob,
       command_line: '--documentation GLOB',
       description: 'Glob that matches available documentation',

lib/jazzy/doc_builder.rb

@@ -250,7 +250,7 @@ def self.new_document(source_module, doc_model)
         doc[:doc_coverage] = source_module.doc_coverage unless
           Config.instance.hide_documentation_coverage
         doc[:structure] = source_module.doc_structure
-        doc[:module_name] = source_module.name
+        doc[:module_name] = source_module.readme_title # historical name
         doc[:author_name] = source_module.author_name
         if source_host = source_module.host
           doc[:source_host_name] = source_host.name
@@ -270,7 +270,7 @@ def self.new_document(source_module, doc_model)
     # @param [String] path_to_root
     def self.document_markdown(source_module, doc_model, path_to_root)
       doc = new_document(source_module, doc_model)
-      name = doc_model.name == 'index' ? source_module.name : doc_model.name
+      name = doc_model.name == 'index' ? source_module.readme_title : doc_model.name
       doc[:name] = name
       doc[:overview] = render(doc_model, doc_model.content(source_module))
       doc[:path_to_root] = path_to_root

lib/jazzy/source_document.rb

@@ -89,7 +89,7 @@ def generated_readme(source_module)
         README
       else
         <<-README
-# #{source_module.name}
+# #{source_module.readme_title}
 
 ### Authors
 

lib/jazzy/source_module.rb

@@ -12,7 +12,7 @@ module Jazzy
   class SourceModule
     include Config::Mixin
 
-    attr_accessor :name
+    attr_accessor :readme_title
     attr_accessor :docs
     attr_accessor :doc_coverage
     attr_accessor :doc_structure
@@ -25,7 +25,8 @@ def initialize(docs, doc_structure, doc_coverage, docset_builder)
       self.docs = docs
       self.doc_structure = doc_structure
       self.doc_coverage = doc_coverage
-      self.name = config.module_names.first # XXX what actually is this type for
+      self.readme_title =
+        config.readme_title || config.module_names.first
       self.author_name = config.author_name
       self.author_url = config.author_url
       self.host = SourceHost.create(config)