Revert "quad: change "modular_quad_pid" to "real_quad""

This reverts commit 4f5322d0

quad/README.md

-# Quadcopter Section
+# Quadcopter
 
-This `quad/` directory contains all code that programs the quadcopter,
-including any C libraries we have written, any HDL to program the Zybo on
+The quad/ directory contains all code that programs the quadcopter. This
+includes any C libraries we have written, any HDL to program the Zybo on
 the quad, and the XSDK main project that runs on the Zybo.
 
 The main quad application is written as a library, and located at:
 ```
-src/quad_app (main function in quad_app.c)
+src/quad_app/quad_app.c
 ```
 
 The main XSDK project that actually runs on the Zybo is located at:
 ```
-xsdk_workspace/real_quad
+xsdk_workspace/modular_quad_pid/main.c
 ```
 
-If you were wondering, we do have the complementary virtual quad easy testing:
-```
-src/virt_quad
-```
+## Building
 
-## Building our Libraries
+### Libraries
 
 To build the libraries:
 ```
@@ -32,21 +29,31 @@ directories:
 cd src/<project> && make
 ```
 
+### XSDK Project
+
+To build the XSDK project that runs on the Zybo (only works on co3050):
+```
+make zybo
+```
+
+To build the Zybo boot image for the SD card (only works on co3050):
+```
+make boot
+```
+
+Disclaimer: The make boot target currently does not work
+
 ## Testing
 
-We have split our code into 2 main sections: application code and hardware code.
-We did that so that we can write tests that run automatically on CI. You just
-can't run automatic tests on hardware code because the environments won't match.
+### Libraries
 
-All CI tests are run using the following target:
+We try to write unit tests for the libraries we've written, since they are
+not tied to the Zybo platform and are able to be run in our CI environment.
 ```
 make test
 ```
 
-This incorporates unit tests (`src/<library>/test`), as well as a few functional
-test scripts (`scripts/tests`) that verify things on the virtual quad.
-
-You can also run the tests for a specific library inside its respective project
+You can also run the test for specific library inside its respective project
 directory:
 ```
 cd src/<project> && make test
@@ -54,6 +61,6 @@ cd src/<project> && make test
 
 ### XSDK Project
 
-We have tests for the hardware-level code, they just have to be run manually.
-You can find these tests along with instructions at
-`xsdk_workspace/read_quad/src/hw_impl_zybo_tests.c`
+The XSDK project implements the hardware interfaces used in the quad app.
+There are tests can be executed from the main function in that XSDK project.
+These tests essentially test each hardware interface.