[docs] Update the readme blueprint to generate instructions for running a codemod locally

We recently had an engineer who was not familiar with npx and could not figure out
how to run a new codemod locally.

I've updated the blueprint to make it clear to new users how to run a codemod locally before
publishing.

Author: jsturgis

commands/global/new.js

@@ -40,7 +40,7 @@ module.exports.handler = async function handler(options) {
 
       ## Local Usage
       \`\`\`
-      npx ${process.cwd()}/${projectName}${cliPath} <TRANSFORM NAME> path/of/files/ or/some**/*glob.js
+      node .${cliPath} <TRANSFORM NAME> path/of/files/ or/some**/*glob.js
       \`\`\`
 
       ## Transforms