add options and target, basic doc

README.md

@@ -1,3 +1,20 @@
 # drone-plugin-make
 
-Drone plugin to run `make` command.
+Drone plugin to run `make` command.
+
+Usage example:
+
+```
+#...
+steps:
+  - name: make
+    image: eumau/drone-plugin-make
+	settings:
+	  targets:
+	    - target1
+		- target2
+	  options:
+	    "-k"
+```
+
+Note that `options` should be provided as a string.

script.sh

@@ -1,2 +1,2 @@
 #!/bin/sh
-make ${PLUGIN_OPTS}
+make ${PLUGIN_OPTIONS} ${PLUGIN_TARGETS/,/ }