docs: Update README.md

Makefile

···
 	$(CC) $(CFLAGS) $(LIB_SRC) $< -o $@
 
 $(BUILD):
+	mkdir -p data
 	mkdir -p $(BUILD)
 
 clean:

README.md

···
 
 ## Usage
 
-First, you have to setup the project.
-
-```sh
-make all
-```
+First, check out the different parts in the project:
 
 This will compile all the necessary executables and put them in a directory
 called: `./.build`. The executables provided are:
···
 
 Remember, this will put all the executables in a directory called `.build`.
 
-Then, launch the metadata server first!
+Then, you have to create the database:
 
+```sh
+./.build/createdb
+```
+
+Now, you can start launching things! First, you want to create the metadata
+server. Like this:
 
 ```sh
 ./.build/metadata-server 127.0.0.1 42069
 ```
 
-Leave this running in the background. Now launch several data nodes in other
-terminals:
+Leave this running in the background. Now, go to a different terminal and launch
+several data nodes in other terminals:
 
 Terminal 1:
 ```sh
···
 
 There is a `./test.sh` file that can help you test out your files. It will create
 a `500MB` file. I tested this with files up to `5GB` so if you want to try that,
-just add another 0 to the `./test.sh` file.
+just add another 0 to the line in `./test.sh` that has the following:
+
+```sh
+cat /dev/random | head -c5000000000 > 500MB.bin
+```