ci: declare least-privilege permissions in workflows (#354)

Author: arpitjain099

.github/workflows/format-check.yml

@@ -3,6 +3,9 @@ name: Format checks
 on:
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   format-check:
     name: FILE FORMAT

.github/workflows/link-check.yml

@@ -3,6 +3,9 @@ name: Link checks
 on:
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   link-check:
     name: LINK checking

.github/workflows/spell-check.yml

@@ -3,6 +3,9 @@ name: Spelling checks
 on:
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   spelling-check:
     name: SPELLING check

.github/workflows/trigger-contribute-site-netlify.yml

@@ -4,6 +4,8 @@ on:
   push:
     branches: [main]
 
+permissions: {}
+
 jobs:
   trigger:
     runs-on: ubuntu-latest