add spellcheck to ci

.github/workflows/spellcheck.yaml

@@ -0,0 +1,11 @@
+name: Spellcheck
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  build:
+    name: Spellcheck
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - uses: rojopolis/[email protected]
+      name: Spellcheck

spellcheck.yaml

@@ -0,0 +1,36 @@
+matrix:
+  - name: markdown
+    sources:
+      - '**/*.md|!beacon-apis/**'
+    aspell:
+      lang: en
+      d: en_US
+      ignore-case: true
+      run-together: true
+      run-together-min: 2
+      run-together-limit: 256
+    dictionary:
+      wordlists:
+        - wordlist.txt
+      encoding: utf-8
+    pipeline:
+    - pyspelling.filters.markdown:
+    - pyspelling.filters.html:
+        comments: false
+        ignores:
+        - code
+        - pre
+  - name: yaml schemas
+    sources:
+      - '**/*.yaml|!beacon-apis/**|!spellcheck.yaml'
+    aspell:
+      lang: en
+      d: en_US
+      run-together: true
+      run-together-min: 2
+      run-together-limit: 256
+    dictionary:
+      wordlists:
+        - wordlist.txt
+      encoding: utf-8
+    pipeline: null

wordlist.txt

@@ -0,0 +1,26 @@
+apis
+bellatrix
+bls
+bn
+cli
+dev
+eth
+http
+https
+json
+mev
+nodejs
+npm
+oapi
+openapi
+ssz
+tbh
+ui
+uint
+unblind
+unblinded
+url
+validators
+validator's
+vc
+wei