Update README.md

Added some steps that may be required

Author: angieh811

backend/README.md

@@ -9,6 +9,8 @@ This is a node app that serves as a REST API backend to plotter. Built using `ex
 
 **MacOS installation instructions**
 
+- Install xcode-select before installing brew
+
 - _Setting up mongoDB using [homebrew](https://brew.sh/)_
 
   - Add mongoDB Homebrew Tap
@@ -29,6 +31,12 @@ This is a node app that serves as a REST API backend to plotter. Built using `ex
   mkdir -p ~/Desktop/data/db
   ```
 
+  - Might neeed to export the dbpath
+
+  ```
+  export PATH="$PATH:/usr/local/mongodb/bin”
+  ```
+
   - To start your mongodb server
 
   ```