Remove markdown support from wit-parser

This is quite old at this point and I'm not aware of anyone using it or
planning to use it, so remove its support here to cut down on the deps
and size of `wit-parser`.

crates/wit-parser/Cargo.toml

@@ -16,7 +16,6 @@ Tooling for parsing `*.wit` files and working with their contents.
 id-arena = "2"
 anyhow = { workspace = true }
 indexmap = { workspace = true, features = ["serde"] }
-pulldown-cmark = { version = "0.9.3", default-features = false }
 unicode-xid = "0.2.2"
 log = { workspace = true }
 url = { workspace = true }

crates/wit-parser/src/ast.rs

@@ -1199,55 +1199,14 @@ impl SourceMap {
     /// interfaces and worlds defined together. Note that each file has its own
     /// personal namespace, however, for top-level `use` and such.
     pub fn push(&mut self, path: &Path, contents: impl Into<String>) {
-        let mut contents = contents.into();
-        if path.extension().and_then(|s| s.to_str()) == Some("md") {
-            log::debug!("automatically unwrapping markdown container");
-            contents = unwrap_md(&contents);
-        }
+        let contents = contents.into();
         let new_offset = self.offset + u32::try_from(contents.len()).unwrap();
         self.sources.push(Source {
             offset: self.offset,
             path: path.to_path_buf(),
             contents,
         });
         self.offset = new_offset;
-
-        fn unwrap_md(contents: &str) -> String {
-            use pulldown_cmark::{CodeBlockKind, CowStr, Event, Options, Parser, Tag};
-
-            let mut wit = String::new();
-            let mut last_pos = 0;
-            let mut in_wit_code_block = false;
-            Parser::new_ext(contents, Options::empty())
-                .into_offset_iter()
-                .for_each(|(event, range)| match (event, range) {
-                    (
-                        Event::Start(Tag::CodeBlock(CodeBlockKind::Fenced(CowStr::Borrowed(
-                            "wit",
-                        )))),
-                        _,
-                    ) => {
-                        in_wit_code_block = true;
-                    }
-                    (Event::Text(text), range) if in_wit_code_block => {
-                        // Ensure that offsets are correct by inserting newlines to
-                        // cover the Markdown content outside of wit code blocks.
-                        for _ in contents[last_pos..range.start].lines() {
-                            wit.push('\n');
-                        }
-                        wit.push_str(&text);
-                        last_pos = range.end;
-                    }
-                    (
-                        Event::End(Tag::CodeBlock(CodeBlockKind::Fenced(CowStr::Borrowed("wit")))),
-                        _,
-                    ) => {
-                        in_wit_code_block = false;
-                    }
-                    _ => {}
-                });
-            wit
-        }
     }
 
     /// Parses the files added to this source map into an [`UnresolvedPackage`].