refactor: use the yml extension for every yaml file

The repository mixed both extensions, the molecule scenario used yml while the role itself used yaml. The yml
extension is the one ansible-galaxy and molecule generate and the one the sibling roles use, so it is applied
throughout.

The first_found lookups in tasks/main.yml name the candidate files explicitly and were adjusted accordingly, otherwise
the role would no longer find its distribution variables and its verification tasks.

Co-authored-by: Copilot <copilot@github.com>

.markdownlint.yml

@@ -0,0 +1,137 @@
+# markdownlint YAML configuration
+# https://github.com/DavidAnson/markdownlint/blob/main/schema/.markdownlint.yaml
+
+# Default state for all rules
+default: true
+
+# Path to configuration file to extend
+extends: null
+
+# MD003/heading-style/header-style - Heading style
+MD003:
+  # Heading style
+  style: "atx"
+
+# MD004/ul-style - Unordered list style
+MD004:
+  style: "dash"
+
+# MD007/ul-indent - Unordered list indentation
+MD007:
+  # Spaces for indent
+  indent: 2
+  # Whether to indent the first level of the list
+  start_indented: false
+
+# MD009/no-trailing-spaces - Trailing spaces
+MD009:
+  # Spaces for line break
+  br_spaces: 2
+  # Allow spaces for empty lines in list items
+  list_item_empty_lines: false
+  # Include unnecessary breaks
+  strict: false
+
+# MD010/no-hard-tabs - Hard tabs
+MD010:
+  # Include code blocks
+  code_blocks: true
+
+# MD012/no-multiple-blanks - Multiple consecutive blank lines
+MD012:
+  # Consecutive blank lines
+  maximum: 1
+
+# MD013/line-length - Line length
+MD013:
+  # Number of characters
+  line_length: 120
+  # Number of characters for headings
+  heading_line_length: 120
+  # Number of characters for code blocks
+  code_block_line_length: 120
+  # Include code blocks
+  code_blocks: false
+  # Include tables
+  tables: false
+  # Include headings
+  headings: true
+  # Strict length checking
+  strict: false
+  # Stern length checking
+  stern: false
+
+# MD022/blanks-around-headings/blanks-around-headers - Headings should be surrounded by blank lines
+MD022:
+  # Blank lines above heading
+  lines_above: 1
+  # Blank lines below heading
+  lines_below: 1
+
+# MD025/single-title/single-h1 - Multiple top-level headings in the same document
+MD025:
+  # Heading level
+  level: 1
+  # RegExp for matching title in front matter
+  front_matter_title: "^\\s*title\\s*[:=]"
+
+# MD026/no-trailing-punctuation - Trailing punctuation in heading
+MD026:
+  # Punctuation characters
+  punctuation: ".,;:!。，；：！"
+
+# MD029/ol-prefix - Ordered list item prefix
+MD029:
+  # List style
+  style: "one_or_ordered"
+
+# MD030/list-marker-space - Spaces after list markers
+MD030:
+  # Spaces for single-line unordered list items
+  ul_single: 1
+  # Spaces for single-line ordered list items
+  ol_single: 1
+  # Spaces for multi-line unordered list items
+  ul_multi: 1
+  # Spaces for multi-line ordered list items
+  ol_multi: 1
+
+# MD033/no-inline-html - Inline HTML
+MD033:
+  # Allowed elements
+  allowed_elements: []
+
+# MD035/hr-style - Horizontal rule style
+MD035:
+  # Horizontal rule style
+  style: "---"
+
+# MD036/no-emphasis-as-heading/no-emphasis-as-header - Emphasis used instead of a heading
+MD036:
+  # Punctuation characters
+  punctuation: ".,;:!?。，；：！？"
+
+# MD041/first-line-heading/first-line-h1 - First line in a file should be a top-level heading
+MD041:
+  # Heading level
+  level: 1
+  # RegExp for matching title in front matter
+  front_matter_title: "^\\s*title\\s*[:=]"
+
+# MD044/proper-names - Proper names should have the correct capitalization
+MD044:
+  # List of proper names
+  names:
+  - gitea
+  # Include code blocks
+  code_blocks: false
+
+# MD046/code-block-style - Code block style
+MD046:
+  # Block style
+  style: "fenced"
+
+# MD048/code-fence-style - Code fence style
+MD048:
+  # Code fence syle
+  style: "backtick"