docs: add README

README.md

@@ -1,4 +1,51 @@
-# todo
+# serverless-plugin-tree-shake
 
-- [ ] tree-shake handler code;
-- [ ] tests;
+Shake the file dependency tree and only include files needed.
+
+## install
+
+```bash
+yarn add --dev serverless-plugin-tree-shake
+```
+
+```bash
+npm install --save-dev serverless-plugin-tree-shake
+```
+
+## usage
+
+```yaml
+plugins:
+  - serverless-plugin-tree-shake
+package:
+  # no need to spend time doing excluding dev dependencies, given that
+  # serverless-plugin-tree-shake does it already
+  excludeDevDependencies: false
+```
+
+##### typescript support
+
+This plugins supports typescript natively. It uses the installed typescript package, reads the appropriate config, and transpiles to js according to that config. You can see examples on the [`__fixtures__`](./test/__fixtures__) that start with `ts-`.
+
+##### individually
+
+This plugins supports bundling functions `individually`. Just use that option accordingly:
+
+```yaml
+package:
+  individually: true
+  excludeDevDependencies: false
+```
+
+##### include and exclude
+
+You can use the `include` and `exclude` global, and per-function, configurations and it will include/exclude the especified files/patterns.
+
+## todo
+
+- [ ] tree shake handlers, not only the file tree
+- [ ] add benchmarks
+
+## license
+
+BSD-3-Clause