Order default Markdown extensions by popularity

md and markdown come first, followed by mdx, qmd, rmd, then the long tail of legacy extensions.

Author: mre

lychee-bin/src/config/mod.rs

@@ -224,7 +224,7 @@ pub(crate) struct Config {
     /// This is useful when the default extensions are not enough and you don't
     /// want to provide a long list of inputs (e.g. file1.html, file2.md, etc.)
     ///
-    /// [default: rmd,qmd,md,mkd,mdx,mdown,mdwn,mkdn,mkdown,markdown,html,htm,css,txt,xml]
+    /// [default: md,markdown,mdx,qmd,rmd,mkd,mkdn,mdwn,mdown,mkdown,html,htm,css,txt,xml]
     #[arg(long, verbatim_doc_comment)]
     extensions: Option<FileExtensions>,
 

lychee-lib/src/types/file.rs

@@ -140,8 +140,11 @@ impl std::fmt::Display for FileType {
 
 impl FileType {
     /// All known Markdown extensions
+    // NOTE: Stored in reverse-popularity order because the `Iterator` impl for
+    // `FileExtensions` pops from the end, so the user-visible default list ends
+    // up as `md, markdown, mdx, qmd, rmd, mkd, mkdn, mdwn, mdown, mkdown`.
     const MARKDOWN_EXTENSIONS: &'static [&'static str] = &[
-        "markdown", "mkdown", "mkdn", "mdwn", "mdown", "mdx", "mkd", "md", "qmd", "rmd",
+        "mkdown", "mdown", "mdwn", "mkdn", "mkd", "rmd", "qmd", "mdx", "markdown", "md",
     ];
 
     /// All known HTML extensions