Make prettierignore consistent with eslintignore

@pmario do you happen to know if there's a way to avoid the duplication here? Can we make prettier use the ignore list from eslint?

.eslintignore

@@ -6,3 +6,6 @@
 /core/modules/utils/diff-match-patch/diff_match_patch_uncompressed.js
 /core/modules/utils/dom/csscolorparser.js
 /plugins/tiddlywiki/*/files/
+/tmp/
+/output/
+ 

.prettierignore

@@ -0,0 +1,10 @@
+# Ignore "third party" code whose style we will not change.
+/boot/sjcl.js
+/core/modules/utils/base64-utf8/base64-utf8.module.js
+/core/modules/utils/base64-utf8/base64-utf8.module.min.js
+/core/modules/utils/diff-match-patch/diff_match_patch.js
+/core/modules/utils/diff-match-patch/diff_match_patch_uncompressed.js
+/core/modules/utils/dom/csscolorparser.js
+/plugins/tiddlywiki/*/files/
+/tmp/
+/output/

.prettierrc.json

@@ -0,0 +1 @@
+{}

bin/test.sh

@@ -2,6 +2,10 @@
 
 # test TiddlyWiki5 for tiddlywiki.com
 
+# Let Prettier check formatting
+
+npm run prettier-check || exit 1
+
 # Run the test edition to run the node.js tests and to generate test.html for tests in the browser
 
 node ./tiddlywiki.js \

package.json

@@ -24,7 +24,8 @@
     "wiki"
   ],
   "devDependencies": {
-    "eslint": "^7.32.0"
+    "eslint": "^8.37.0",
+    "prettier": "^2.8.7"
   },
   "bundleDependencies": [],
   "license": "BSD",
@@ -32,6 +33,10 @@
     "node": ">=0.8.2"
   },
   "scripts": {
-    "lint": "eslint ."
+    "lint": "eslint .",
+	"prettier-check": "npx prettier --check .",
+	"prettier-write": "npx prettier --write ."
+  },
+  "dependencies": {
   }
 }