readme: added links to uncommon non-self-explanatory dependencies

README.md

@@ -264,7 +264,7 @@ Listed in `package.json`, installed with `npm ci`, not vendored.
 
 #### Dev dependencies (build/compile-time)
 
-* `tap`, a test framework.
+* `tap`, a test framework (https://node-tap.org/).
 * `typescript`, because it's so much easier to write even small projects in TS than in JS.
 * `@tsconfig/strictest`, to avoid having to enable all the strict TS compiler options manually.
 * `eslint`, for linting.
@@ -281,7 +281,7 @@ Listed in `package.json`, installed with `npm ci`, not vendored.
 * `express`, because I needed a minimal server framework to handle requests and serve static files.
 * `body-parser`, to handle POST requests in express.
 * `preact`, `preact-render-to-string`, to render intermediate JSX code to HTML
-    (because I'm using JSX as a template language on backend).
+    (because I'm using JSX as a template language on backend) (https://preactjs.com/).
 
 #### Frontend dependencies (runtime)