tests: Use raw multiline strings in test cases and add deep nesting test

- Replace escaped newlines with raw multiline strings for better readability
- Add comprehensive deep nested list test case with 4 levels of nesting
- Use clear hierarchical naming (Item 1, 1.1, 1.1.1, 1.1.1.1) for easy navigation

prompts:
- "add a test case to test_document_parsing_snapshots for a more complex 4 level nesting with lots of interesting variations"
- "run tests"
- "can we use raw multiline strings in the cases in test_document_parsing_snapshots lib.rs:31"
- "rename the bullets in deep to be easier to follow - use 1.2.3 names"
- "commit"
- "prompts?"
- "no, include the prompts in the commit you forgetful moron"

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: timabell

src/lib.rs

@@ -17,13 +17,32 @@ mod unit_tests {
     use rstest::rstest;
 
     #[rstest]
-    #[case("- First item\n- Second item\n- Third item", "simple_bullet_list")]
+    #[case(r#"- First item
+- Second item
+- Third item"#, "simple_bullet_list")]
     #[case(
-        "- Parent item\n  - Child item\n  - Another child\n- Second parent",
+        r#"- Parent item
+  - Child item
+  - Another child
+- Second parent"#,
         "nested_bullet_list"
     )]
     #[case("- Single item", "single_item")]
     #[case("", "empty_markdown")]
+    #[case(
+        r#"- Item 1
+  - Item 1.1
+    - Item 1.1.1
+      - Item 1.1.1.1
+      - Item 1.1.1.2
+    - Item 1.1.2
+  - Item 1.2
+    - Item 1.2.1
+- Item 2
+  - Item 2.1
+- Item 3"#,
+        "deep_nested_list"
+    )]
     fn test_document_parsing_snapshots(#[case] markdown: &str, #[case] name: &str) {
         use std::path::PathBuf;
         let doc = parsing::parse_markdown(markdown, PathBuf::from("test.md"));

src/snapshots/markdown_neuraxis__unit_tests__deep_nested_list.snap

@@ -0,0 +1,39 @@
+---
+source: src/lib.rs
+expression: doc.content
+---
+- BulletList:
+    items:
+      - content: Item 3
+        level: 0
+        children: []
+      - content: Item 2
+        level: 0
+        children:
+          - content: Item 2.1
+            level: 1
+            children: []
+      - content: Item 1
+        level: 0
+        children:
+          - content: Item 1.2
+            level: 1
+            children:
+              - content: Item 1.2.1
+                level: 2
+                children: []
+          - content: Item 1.1
+            level: 1
+            children:
+              - content: Item 1.1.2
+                level: 2
+                children: []
+              - content: Item 1.1.1
+                level: 2
+                children:
+                  - content: Item 1.1.1.2
+                    level: 3
+                    children: []
+                  - content: Item 1.1.1.1
+                    level: 3
+                    children: []