Update readme

README.MD

@@ -30,3 +30,29 @@ This module wouldn't happen without great help from following people:
 - [Jos Lieben](https://twitter.com/joslieben)
 
 It is recommended to use **PowerShell 7** or higher. While the module does work in PowerShell 5.1 it has some issues with cookies most likely related to lenght of password.
+
+## Installing
+
+Everyone can install this module from **PowerShellGallery** hosted by Microsoft. It's recommended way to work with the module.
+Version on **PowershellGallery** is optimized for speed and signed. Using code from **GitHub** is **recommended for development**.
+
+```powershell
+Install-Module -Name O365Essentials -AllowClobber -Force
+```
+
+Force and AllowClobber aren't necessary, but they do skip errors in case some appear.
+
+## Updating
+
+```powershell
+Update-Module -Name O365Essentials
+```
+
+That's it. Whenever there's a new version, you run the command, and you can enjoy it. Remember that you may need to close, reopen PowerShell session if you have already used module before updating it.
+
+**The essential thing** is if something works for you on production, keep using it till you test the new version on a test computer. I do changes that may not be big, but big enough that auto-update may break your code. For example, small rename to a parameter and your code stops working! Be responsible!
+
+## Changelog
+
+- 0.0.1 - 2021.08.19
+  - First version