chore: error on cspell issues in docs (#3886)

# Description

## Problem\*

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

## Summary\*

This PR updates the spellcheck workflow to run a separate pass over the
docs which will error rather than raising a warning. This is as it's
more important to catch spelling issues in the docs rather than in the
code (plus the docs is going to use fewer non-standard-english library
names, etc. so false positives will be rarer.

## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** 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.

.github/workflows/spellcheck.yml

@@ -8,6 +8,32 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  spellcheck:
-    name: Spellcheck
-    uses: noir-lang/.github/.github/workflows/spellcheck.yml@main
+  code:
+    name: Code
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Check spelling
+        uses: streetsidesoftware/cspell-action@v2
+        with:
+          strict: false # Do not fail, if a spelling mistake is found (This can be annoying for contributors)
+          incremental_files_only: true # Run this action on files which have changed in PR
+          files: |
+            **/*.{md,rs}
+
+  docs:
+    name: Documentation
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Check spelling
+        uses: streetsidesoftware/cspell-action@v2
+        with:
+          strict: true # Documentation has higher standards for correctness.
+          incremental_files_only: true # Run this action on files which have changed in PR
+          files: |
+            ./docs/**/*.md

cspell.json

@@ -124,6 +124,7 @@
         "srem",
         "stdlib",
         "struct",
+        "structs",
         "subexpression",
         "subshell",
         "subtyping",
@@ -148,5 +149,8 @@
         "wasi",
         "Weierstraß",
         "zshell"
+    ],
+    "ignorePaths": [
+        "./**/node_modules/**"
     ]
 }