Add a spell check workflow

.github/workflows/typos.yml

@@ -0,0 +1,18 @@
+name: Spell Check
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  typos:
+    name: typos
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: crate-ci/typos@v1.49.0

_typos.toml

@@ -0,0 +1,22 @@
+# Configuration for typos (https://github.com/crate-ci/typos)
+
+[default.extend-words]
+# OT is the order type parameter of the calculus operators
+OT = "OT"
+# WrappOp is the wrapper operator generated by @calculus_operator
+Wrapp = "Wrapp"
+# opf is the symbol built by Symbol(:op, f) in the operator definitions
+opf = "opf"
+# TensorSpaceND
+ND = "ND"
+# local variables
+BA = "BA"
+iy = "iy"
+kend = "kend"
+shft = "shft"
+# SIAM J. Sci. Comput.
+Comput = "Comput"
+# spelling variant used in a section header
+Overrideable = "Overrideable"
+# the name referred to by a TODO comment
+SPECIALOPS = "SPECIALOPS"