Update README.md

Author: ViliusSutkus89

README.md

@@ -3,9 +3,18 @@
 ![Build & Test](https://github.com/android-actions/setup-android/workflows/Build%20&%20Test/badge.svg)
 
 This action sets up the Android SDK tools by:
- - Downloading the SDK commandline tools
- - Accepting the SDK licenses
- 
+ - Downloading the SDK commandline tools, if the current version (7.0) is not found in either `$ANDROID_SDK_ROOT` or `$HOME/.android/sdk`.
+ - Accepting the SDK licenses.
+ - Installing `tools` and `platform-tools`.
+ - Adding `platform-tools` (contains adb) and `cmdline-tools/7.0/bin` (contains sdkmanager) to `$PATH`.
+ - Setting up problem [matchers](/matchers.json).
+
+On Windows 2016 runners, this action also checks if `$ANDROID_SDK_ROOT` path contains spaces.
+If it does - it moves SDK to a path without spaces. This is needed because spaces are highly problematic:
+```
+C:\windows\system32\cmd.exe /D /S /C ""C:\Program Files (x86)\Android\android-sdk\cmdline-tools\3.0\bin\sdkmanager.bat" --licenses"
+Error: Could not find or load main class Files
+```
 
 # Usage