chore: Fix docs (#6035)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*



## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [ ] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

noir_stdlib/src/meta/ctstring.nr

@@ -3,7 +3,7 @@ use crate::append::Append;
 impl CtString {
     // docs:start:new
     comptime fn new() -> Self {
-        // docs::end::new
+        // docs:end:new
         "".as_ctstring()
     }