Update README

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

README.md

@@ -9,4 +9,46 @@ New features are not likely to be added, since I expect compton to become irrele
 
 The original README can be found [here](README_orig.md)
 
-You are welcomed to submit pull requests.
+## Build
+
+### Dependencies
+
+Assuming you already have all the usual building tools installed (e.g. gcc, make, etc.), you still need:
+
+* libx11
+* libXext
+* xproto
+* xcb
+* xcb-damage
+* xcb-xfixes
+* xcb-shape
+* xcb-renderutil
+* xcb-render
+* xcb-randr
+* xcb-composite
+* xcb-image
+* xcb-xinerama (optional, disable with `NO_XINERAMA=1` make flag)
+* pixman
+* libdbus (optional, disable with the `NO_DBUS=1` make flag)
+* libconfig (optional, disable with the `NO_LIBCONFIG=1` make flag)
+* libGL (optional, disable with the `NO_OPENGL=1` make flag)
+* libpcre (optional, disable with the `NO_REGEX_PCRE=1` make flag)
+
+To build the documents, you need `asciidoc`
+
+### How to build
+
+```bash
+$ make
+$ make install
+```
+
+## How to Contribute
+
+### Code
+
+You can look at the [Projects](https://github.com/yshui/compton/projects) page, and see if there is anything interests you. Or you can take a look at the [Issues](https://github.com/yshui/compton/issues).
+
+### Non-code
+
+Even if you don't want to contribute code, you can still contribute by compiling and running this branch, and report any issue you can find.