Update performance.md (#1837)

Author: cspotcode

website/docs/performance.md

@@ -6,14 +6,18 @@ These tricks will make ts-node faster.
 
 ## Skip typechecking
 
-It is often better to use `tsc --noEmit` to typecheck as part of your tests or linting. In these cases, ts-node can skip typechecking.
+It is often better to typecheck as part of your tests or linting.  You can use `tsc --noEmit` to do this.  In these cases, ts-node can skip typechecking making it much faster.
+
+To skip typechecking in ts-node, do one of the following:
 
 * Enable [swc](./swc.md)
   * This is by far the fastest option
 * Enable [`transpileOnly`](./options.md#transpileonly) to skip typechecking without swc
 
 ## With typechecking
 
+If you absolutely must use ts-node for typechecking:
+
 * Avoid dynamic `require()` which may trigger repeated typechecking; prefer `import`
 * Try with and without `--files`; one may be faster depending on your project
 * Check `tsc --showConfig`; make sure all executed files are included