add to readme: all predefined template variables

README.md

@@ -99,6 +99,25 @@ If you use the `include` directive in your modified `default.html` template
 file, `repo2html` will look for the templates to be included in that same
 specified directory, where your `default.html` template lives.
 
+The following variables are available to templates:
+
+- source_files_list: a list of all the files in the repo.
+- repository_description: a short description of the repo, if provided. See configuration.
+- repository_name: the name of the repo. See configuration.
+- repository_path: the URL path from the forge root to the repo.
+- repository_path_parent: repository_path without the repo itself.
+- repository_ancestors: a list of each path element in repository_path_parent
+- readme_file: the filename of the README file, if any. used for the "about" link.
+- license_file: the filename of the LICENSE file, if any. used for the "license" link.
+- issues_file: if any files exist in ISSUES/, this will be set to "ISSUES".
+- repo2html_version: the blob hash of main.scm in this repository.
+- source_file: the filename of the file being rendered.
+- root: always "" (TODO: omit this?)
+- elements: a list of each path element leading to the file being rendered
+- basename: the filename being rendered, with one extension removed
+- extension: the extension removed in basename
+- relative_root: "html/" if the current file is "/index.html" otherwise ""
+
 ## Configuration
 
 `repo2html` understands the following configuration settings.
@@ -200,10 +219,10 @@ Third-party-hosted services that will host browsable code repositories.
 - [Codeberg](https://codeberg.org/)
 - [sourcehut](https://sourcehut.org/)
 - [GitLab](https://gitlab.com/)
-- [Bitbucket](https://bitbucket.org/product/)
 - [SourceForge](https://sourceforge.net/)
-- GitHub
-- [pagure](https://pagure.io/pagure)
+- Red Hat [pagure](https://pagure.io/pagure)
+- Atlassian Bitbucket
+- Microsoft GitHub
 
 ## Todos