Added readme on getting course data

schedules_api/db/README.md

+# Data Scrapers
+
+This directory houses the different scrapers that are used to generate the
+various .json files that are loaded into the database on startup. Each scraper
+is documented below:
+
+## Scrapers
+
+### George Mason University (GMU)
+
+George Mason University does not provide a public endpoint for us to source data
+from. Instead we will be downloading a report from the database server that has
+all of the courses in the schools history. This report is an XLSX file, and can
+be simply converted into the .json format by using the included script.
+
+#### To Download the XLSX File
+
+1. Go to the [MicroStrategy site](https://microstrategy.gmu.edu/MicroStrategy/servlet/mstrWeb)
+and sign in as a "Guest User."
+
+2. Click on `GMU Public Reports` > `Shared Reports` > `Course Enrollment` > `Course Search - All Sections`.
+   To do this right, you will need to make sure you click on `Export` when you mouse over Course Search.
+
+3. Select the semester that you want and click on the arrow to bring it into your query.
+
+3. Click `Export` (in the lower left hand corner).