Clarify use

Author: adam-lynch

README.md

@@ -2,9 +2,9 @@
 
 Adds rudimentary [TypeScript](https://www.typescriptlang.org/) support to [AVA](https://avajs.dev).
 
-This is designed to work for projects that precompile TypeScript. It allows AVA to load the compiled JavaScript, while configuring AVA to treat the TypeScript files as test files.
+This is designed to work for projects that precompile their TypeScript code, including tests. It allows AVA to load the resulting JavaScript, while configuring AVA to use the TypeScript paths.
 
-In other words, say you have a test file at `src/test.ts`. You've configured TypeScript to output to `build/`. Using `@ava/typescript` you can run the test using `npx ava src/test.ts`.
+In other words, say you have a test file at `src/test.ts`. You've configured TypeScript to output to `build/`. Using `@ava/typescript` you can run the `build/test.js` file using `npx ava src/test.ts`. AVA won't pick up any of the JavaScript files present in the `build/` directory, unless they have a TypeScript counterpart in `src/`.
 
 ## Enabling TypeScript support