Update README.md

Author: juanfranblanco

README.md

@@ -1,5 +1,48 @@
 # Nethereum.Unity
-Nethereum 472 AOT runtime dlls, please check Nethereum releases for more information, extra components, or other versions (net461, net35, netstandard)  https://github.com/Nethereum/Nethereum/releases, example of usage can be found at https://github.com/Nethereum/Unity3dSampleTemplate.
 
+Nethereum 472 / Netstandard AOT runtime dlls, please check Nethereum releases for more information, extra components, or other versions (net461, net35, netstandard)  https://github.com/Nethereum/Nethereum/releases.
+
+Example of usage can be found at https://github.com/Nethereum/Unity3dSampleTemplate.
+
+## Package installation instructions
+
+#### Install via Package Manager using OpenUpm
+
+* nopen Edit/Project Settings/Package Manager
+* add a new Scoped Registry (or edit the existing OpenUPM entry)
+  
+    **Name** package.openupm.com
+
+    **URL** https://package.openupm.com
+
+    **Scope(s)** com.nethereum.unity
+* click Save or Apply
+* open Window/Package Manager
+* click +
+* select Add package by name... or Add package from git URL...
+* paste com.nethereum.unity into name
+* paste 4.19.2 into version (or your preferred one)
+* click Add
+
+
+Alternatively, merge the snippet to Packages/manifest.json (https://docs.unity3d.com/Manual/upm-manifestPrj.html)
+```json
+{
+    "scopedRegistries": [
+        {
+            "name": "package.openupm.com",
+            "url": "https://package.openupm.com",
+            "scopes": [
+              "com.nethereum.unity"
+            ]
+        }
+    ],
+    "dependencies": {
+        "com.nethereum.unity": "4.19.2"
+    }
+}
+```
+
+### Install using Git
 
 To add this package as a dependency just use the github url, more info can be found here: https://docs.unity3d.com/Manual/upm-git.html