add module tutorial and more preview images to README.md

README.md

@@ -1,7 +1,9 @@
 # candybar
 a stupidly simple modular statusbar
 
-![preview](https://img.donut.gq/1661519970.png)
+![preview 0](https://img.donut.gq/1661519970.png)
+![preview 1](https://cdn.discordapp.com/attachments/961749313480953887/1012981184764059768/image.png)
+![preview 2](https://imgs.asia/images/2022/08/27/2022-08-27-092211_3840x1080_scrot.png)
 
 ## usage
 **candybar** only outputs the text that should be shown on the bar, which makes it useable on different applications.
@@ -30,3 +32,35 @@ export CSI=$'\e'"["
 export PROMPT="${CSI}s${CSI}1;$((LINES-1))r${CSI}$LINES;1f%S%1v%s${CSI}K${CSI}u${PROMPT}"
 ```
 
+## writing modules
+writing candybar modules is very easy. modules can be written in any programming language.
+
+first, open up the modules.sh file. create a new function with, for example, the name `module_foo()`.
+```sh
+module_foo() {
+	# uh, so what now?
+}
+```
+next, if you are using POSIX SH to write your module, just write your script in the function.
+
+for this example, we'll be writing a module that outputs the current date.
+```sh
+module_foo() {
+	# remember to keep the ${bar}, ${1}, and ${2} here!
+	export bar="${bar}${1}$(date)${2}"
+}
+```
+if you are using a different language, write your module and then run it with sh.
+```sh
+module_foo() {
+	export output="$(/path/to/program)"
+	export bar="${bar}${1}${output}${2}"
+}
+```
+now add a line for your module in the config.sh, for example:
+```sh
+module_foo	"Date:"		" | "
+```
+you're done! run candybar to see the results.
+
+remember that if you have configured candybar to be used in zsh, tmux or dwm like in this README, you won't have to restart candybar!