add installation note for mainnet network

Author: woodser

docs/installing.md

@@ -1,18 +1,14 @@
-# Set up environment
+> [!note]
+> Trying to install Haveno for mainnet?
+> 
+> Find a third party network and use their installer or build their repository. We do not operate or officially endorse any mainnet network.
 
-These are the steps needed to build Haveno and test it on our test network or locally.
+# Set up environment
 
+These are the steps needed to build Haveno. You can build the offical repository to test it on our test network or locally.
 ## Install dependencies
 
-On Linux and macOS, install Java JDK 21:
-
-```
-curl -s "https://get.sdkman.io" | bash
-sdk install java 21.0.2.fx-librca
-```
-
-On Windows, install MSYS2 and Java JDK 21:
-
+On Windows, first install MSYS2:
   1. Install [MSYS2](https://www.msys2.org/).
   2. Start MSYS2 MINGW64 or MSYS MINGW32 depending on your system. Use MSYS2 for all commands throughout this document.
   4. Update pacman: `pacman -Syy`
@@ -21,8 +17,13 @@ On Windows, install MSYS2 and Java JDK 21:
       64-bit: `pacman -S mingw-w64-x86_64-toolchain make mingw-w64-x86_64-cmake git`
 
       32-bit: `pacman -S mingw-w64-i686-toolchain make mingw-w64-i686-cmake git`
-  6. `curl -s "https://get.sdkman.io" | bash`
-  7. `sdk install java 21.0.2.fx-librca`
+
+Install Java JDK 21:
+
+```
+curl -s "https://get.sdkman.io" | bash
+sdk install java 21.0.2.fx-librca
+```
 
 ## Build Haveno