Move using https in development to its own file

docusaurus/docs/using-https-in-development.md

@@ -0,0 +1,32 @@
+---
+id: using-https-in-development
+title: Using HTTPS in Development
+---
+
+> Note: this feature is available with `react-scripts@0.4.0` and higher.
+
+You may require the dev server to serve pages over HTTPS. One particular case where this could be useful is when using [the "proxy" feature](#proxying-api-requests-in-development) to proxy requests to an API server when that API server is itself serving HTTPS.
+
+To do this, set the `HTTPS` environment variable to `true`, then start the dev server as usual with `npm start`:
+
+#### Windows (cmd.exe)
+
+```cmd
+set HTTPS=true&&npm start
+```
+
+(Note: the lack of whitespace is intentional.)
+
+#### Windows (Powershell)
+
+```Powershell
+($env:HTTPS = $true) -and (npm start)
+```
+
+#### Linux, macOS (Bash)
+
+```bash
+HTTPS=true npm start
+```
+
+Note that the server will use a self-signed certificate, so your web browser will almost definitely display a warning upon accessing the page.