Add note about renaming to docs

It's way easier to add a note to the guides than to redo all the images,
etc. We have more important things to spend our time on, but if someone
wants to redo them, you are very welcome!

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

docs/guides/minio-image-upload.md

@@ -1,6 +1,8 @@
-Minio Guide for HackMD
+Minio Guide for CodiMD
 ===
 
+***Note:** This guide was written before the renaming. Just replace `HackMD` with `CodiMD` in your mind :smile: thanks!*
+
 1. First of all you need to setup Minio itself.
 
    Please refer to the [official Minio docs](https://docs.minio.io/) for an