docs: add basic fetch & company docs (nodejs#1810)

Co-authored-by: vedanth bora <75097551+VedanthB@users.noreply.github.com>

docs/api/Fetch.md

@@ -0,0 +1,25 @@
+# Fetch
+
+Undici exposes a fetch() method starts the process of fetching a resource from the network.
+
+Documentation and examples can be found on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/fetch).
+
+## File
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/File)
+
+## FormData
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/FormData)
+
+## Response
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Response)
+
+## Request
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Request)
+
+## Header
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Headers)

docsify/sidebar.md

@@ -10,6 +10,7 @@
   * [ProxyAgent](/docs/api/ProxyAgent.md "Undici API - ProxyAgent")
   * [Connector](/docs/api/Connector.md "Custom connector")
   * [Errors](/docs/api/Errors.md "Undici API - Errors")
+  * [Fetch](/docs/api/Fetch.md "Undici API - Fetch")
   * [MockClient](/docs/api/MockClient.md "Undici API - MockClient")
   * [MockPool](/docs/api/MockPool.md "Undici API - MockPool")
   * [MockAgent](/docs/api/MockAgent.md "Undici API - MockAgent")