update readme

README.md

@@ -1,19 +1,38 @@
 # pg_extism
 
-## Run Examples:
+**Note**: This is an experimental SDK.
 
+## Getting started
+Make sure [`plv8`](https://github.com/plv8/plv8) is installed:
+```sql
+create extension plv8;
 ```
+
+Generate sql functions:
+```
+npm install
 npm run build
+```
 
-node --experimental-wasi-unstable-preview1 ./examples/node.js wasm/config.wasm
+Now you can find a `index.sql` in `dist`. Run the sql script in your database.
+This gives you two functions: `extism_create_plugin`, `extism_call`.
 
-deno run -A ./examples/deno.js ./wasm/config.wasm
+## Use pg_extism
 
-bun run ./examples/node.js wasm/config.wasm
+Assume you have a table called `plugins`:
+```sql
+CREATE TABLE public.plugins (
+	id int4 GENERATED ALWAYS AS IDENTITY( INCREMENT BY 1 MINVALUE 1 MAXVALUE 2147483647 START 1 CACHE 1 NO CYCLE) NOT NULL,
+	"data" bytea NULL,
+	"name" varchar NULL,
+	CONSTRAINT plugins_pk PRIMARY KEY (id)
+);
 ```
 
-## Update `extism-kernel.wasm`:
-We are shipping an embedded kernel in base64 form in plugin.ts. To update it, you can run these commands:
+Insert a few plugins into the table. And then call:
+
+```
+select extism_call(data, 'count_vowels', 'Hello World!') from plugins where id = 2;
 ```
-make update-kernel
-```
+
+**Note:** this assumes the plugin with id `2` has a function called `count_vowels`. You can find the plugin [here](https://github.com/extism/plugins/releases).