add build instructions to the readme

README.md

@@ -2,3 +2,21 @@
 ### a rudimentary random string password generator
 
 For demo purposes only
+
+## Build
+
+**Bare Bones**
+```bash
+mkdir build
+g++ -o build/passwdgen ./passwdgen.cpp
+```
+
+**From CMAKE**
+```bash
+mkdir build
+cd build
+cmake ..
+make 
+```
+
+Then, just copy the compiled binary to somewhere on your $PATH