Add more known modes for intelligent indent level guessing

Namely `dockerfile-mode`, `graphql-mode`, `html-mode`, `ruby-mode`,
`svelte-mode`, and `yaml-mode`.

CHANGELOG.md

@@ -3,6 +3,12 @@
 All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog].
 
+## Unreleased
+
+### Enhancements
+* Intelligent indent level guessing is now available for Dockerfile, GraphQL,
+  HTML, Ruby, Svelte, and YAML modes ([#258]).
+
 ## 4.0 (released 2023-11-23)
 ### Breaking changes
 * The order of entries in `apheleia-mode-alist` is no longer as

apheleia-utils.el

@@ -37,6 +37,9 @@ always returns nil to defer to the formatter."
             (cl-case major-mode
               (css-mode 'css-indent-offset)
               (css-ts-mode 'css-indent-offset)
+              (dockerfile-mode 'dockerfile-indent-offset)
+              (graphql-mode 'graphql-indent-level)
+              (html-mode 'sgml-basic-offset)
               (js-jsx-mode 'js-indent-level)
               (js-ts-mode 'js-indent-level)
               (js-mode 'js-indent-level)
@@ -46,11 +49,14 @@ always returns nil to defer to the formatter."
               (json-mode 'js-indent-level)
               (json-ts-mode 'json-ts-mode-indent-offset)
               (nxml-mode 'nxml-child-indent)
+              (ruby-mode 'ruby-indent-level)
               (scss-mode 'css-indent-offset)
+              (svelte-mode 'svelte-basic-offset)
               (web-mode 'web-mode-indent-style)
               (tsx-ts-mode 'typescript-ts-mode-indent-offset)
               (typescript-mode 'typescript-indent-level)
-              (typescript-ts-mode 'typescript-ts-mode-indent-offset))))
+              (typescript-ts-mode 'typescript-ts-mode-indent-offset)
+              (yaml-mode 'yaml-indent-offset))))
 
     (when-let ((indent (and indent-var
                             (boundp indent-var)