Update README

README.md

@@ -29,3 +29,32 @@ jobs:
           verbose: true
           disable-auto-clean: false
 ```
+
+## Inputs
+
+```yml
+environments:
+  description: Process specified environments (comma separated).
+  required: false
+targets:
+  description: Process specified targets (comma separated).
+  required: false
+project-dir:
+  description: Specify the path to project directory. By default, project-dir is equal to current working directory (CWD).
+  required: false
+project-conf:
+  description: Process project with a custom platformio.ini
+  required: false
+jobs:
+  description: Control a number of parallel build jobs. Default is a number of CPUs in a system.
+  required: false
+silent:
+  description: Suppress progress reporting.
+  required: false
+verbose:
+  description: Shows detailed information when processing environments.
+  required: false
+disable-auto-clean:
+  description: Disable auto-clean of build_dir when platformio.ini or src_dir (project structure) have been modified.
+  required: false
+```