add installation note for mainnet network

Author: woodser

docs/installing.md

@@ -1,18 +1,15 @@
 # Set up environment
 
-These are the steps needed to build Haveno and test it on our test network or locally.
+These are the steps needed to build Haveno. You can 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
-```
+> [!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 endorse any mainnet network.
 
-On Windows, install MSYS2 and Java JDK 21:
+## Install dependencies
 
+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`
@@ -21,12 +18,17 @@ 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
 
-If it's the first time you are building Haveno, run the following commands to download the repository, the needed dependencies, and build the latest release:
+If it's the first time you are building Haveno, run the following commands to download the repository, the needed dependencies, and build the latest release. If using a third party network, replace the repository URL with theirs:
 
 ```
 git clone https://github.com/haveno-dex/haveno.git