Add a pointer to Android build doc and a pointer to Hello World sample (#42345)

* Update README.md

* Update docs/workflow/building/mono/README.md

Co-authored-by: Larry Ewing <lewing@microsoft.com>
* Update README.md

Resolve Egor's feedback

Co-authored-by: Larry Ewing <lewing@microsoft.com>

diff --git a/docs/workflow/building/mono/README.md b/docs/workflow/building/mono/README.md
index 00bf920..1891abc 100644 (file)
--- a/docs/workflow/building/mono/README.md
+++ b/docs/workflow/building/mono/README.md
@@ -53,6 +53,14 @@ The build has a number of options that you can learn about using build -?.
 
 See the instructions in [../libraries/webassembly-instructions.md].
 
+### Android
+
+See the instructions for [Testing Android](../../testing/libraries/testing-android.md)
+
+### IOS
+
+See the instructions for [Testing IOS](../../testing/libraries/testing-apple.md)
+
 ## Packages
 
 To generate nuget packages:
@@ -72,6 +80,14 @@ The following packages will be created under `artifacts\packages\<configuration>
 - `transport.Microsoft.NETCore.Runtime.Mono.<version>-dev.<number>.1.nupkg`
 - `transport.runtime.<OS>.Microsoft.NETCore.Runtime.Mono.<version>-dev.<number>.1.nupkg`
 
+## To get started with "Hello World"
+
+Try the sample at `src/mono/netcore/sample/HelloWorld`.
+To run this sample, from the above folder
+```cd ../..
+make run-sample
+```
+
 ## Important Notes
 
 Test binaries are not yet available for mono.