Add HTTPS Upgrade to Readme

README.md

@@ -96,6 +96,17 @@ The [development stack page](https://github.com/poanetwork/blockscout/wiki/Devel
   8. Update your JSON RPC Endpoint in `apps/explorer/config/dev/` and `apps/indexer/config/dev/`
   For the `variant` chosen in step 7, enter the correct information for the corresponding JSON RPC Endpoint in `parity.exs`, `geth.exs`, or `ganache.exs`
   
+  9. Enable HTTPS in development. The Phoenix server only runs with HTTPS now.
+     * `cd apps/block_scout_web`
+     * `mix phx.gen.cert blockscout blockscout.local`
+     * Add blockscout and blockscout.local to your `/etc/hosts`
+     ```
+        127.0.0.1       localhost blockscout blockscout.local
+        255.255.255.255 broadcasthost
+        ::1             localhost blockscout blockscout.local
+      ```
+      * If using Chrome, Enable `chrome://flags/#allow-insecure-localhost`.
+
   9. Start Phoenix Server.  
   `mix phx.server`