Update esprima bin wrapper and explain in README

esprima-bin-wrapper/README.md

@@ -1,4 +1,4 @@
-# Instructions
+# Usage Instructions
 
 (Don't forget to do `npm install` (or `yarn`)!!)
 
@@ -10,3 +10,26 @@ node esprima-bin-wrapper.js -m path_with_js_files/ > result.json
 ```
 
 to get a result.json file with the AST of all the JS scripts in `path_with_js_files`.
+
+
+# How is it used from Pharo
+
+Pharo code invokes `dist/esprima-bin-wrapper.node.js`. 
+Note that is not exactly the file referenced in previous section, but the output of webpack.
+
+- Invoked js file: `esprima-bin-wrapper/dist/esprima-bin-wrapper.node.js`
+- Invocation from Pharo: `src/Hunter-AST.package/HNEsprimaWrapper.class/class/esprimaWrapperPathRelativeTo..st`
+
+
+# Update Instructions
+
+Following, steps to update dependencies and re-build the webpack output.
+```
+npm install -g npm-check-updates
+ncu -u
+npm update
+npm run build
+```
+After, open Hunter and run tests in Pharo Test Runner.
+
+A reference: https://github.com/dorellang/hunter/issues/57