Add INSTALL.md for macOS and Ubuntu . Point the README to it.

Signed-off-by: jefft0 <[email protected]>

INSTALL.md

@@ -0,0 +1,136 @@
+# Build gomobile-ipfs
+
+These are instructions to build gomobile-ipfs.
+
+<!-- markdownlint-disable MD034 -->
+
+## Prerequisites
+
+* Required: Python pip3 version >= 19.2
+* Required: Go version 1.17 or 1.18
+* Required on macOS: Command Line Developer Tools
+* Required on macOS 10.15: Python modules pystache and yaml
+* Required to build for Android: Android Studio
+* Required to build on macOS: Xcode
+* Required to build for iOS: cocoapods
+
+Following are the steps to install each prerequisite (if it's needed for your
+build target).
+
+### macOS 10.15, macOS 11 and macOS 12
+
+To install the Command Line Developer Tools, in a terminal enter:
+
+    xcode-select --install
+
+After the Developer Tools is installed, we need to make sure it is updated. In
+System Preferences, click Software Update and update it if needed.
+
+macOS 15 only: We need to manually update pip3. In a terminal, enter:
+
+    sudo python3 -m pip install --upgrade pip
+
+Install Go 1.17 or 1.18 with a package manager, or follow instructions at
+https://go.dev/dl .
+
+To install Android Studio, download and install the latest
+android-studio-{version}-mac.dmg from https://developer.android.com/studio .
+(Tested with Chipmunk 2021.2.1 .)
+
+To install cocoapods, we need brew. To install brew, follow the instructions at
+https://brew.sh . To install cocoapods, in a terminal enter:
+
+    brew install cocoapods
+
+### Ubuntu 18.04, 20.04 and 22.04
+
+Install go 1.17 or 1.18 with a package manager, or follow instructions at
+https://go.dev/dl.
+
+To install Python pip3, in a terminal enter:
+
+    sudo apt install python3-pip
+
+To install Android Studio, download the latest
+android-studio-{version}-linux.tar.gz from
+https://developer.android.com/studio . (Tested with Chipmunk 2021.2.1 .)
+In a terminal, enter the following with the correct {version}:
+
+    sudo tar -C /usr/local -xzf android-studio-{version}-linux.tar.gz
+
+To launch Android Studio, in a terminal enter:
+
+    /usr/local/android-studio/bin/studio.sh &
+
+## Build for Android
+
+* Launch Android Studio and accept the default startup options. Create a new
+  default project (so that we get the main screen).
+* On the Tools menu, open the SDK Manager.
+* In the "SDK Platforms" tab, check "Android 11.0 (R)".
+* In the "SDK Tools" tab, click "Show Package Details". Expand
+  "NDK (Side by side)" and check "23.1.7779620".
+* Click OK to install and close the SDK Manager.
+* If you are not plugging in a real phone, on the Tools menu open the Device
+  Manager and create an Android 10 device.
+
+Open a new terminal to get the setup from the installers. To set the environment
+variables, enter the following, depending on your platform. (You must do this
+each time you start a new terminal, or put the commands in ~/.bash_profile .)
+
+macOS:
+
+    export GOPATH="$HOME/go"
+    export PATH="$PATH:$GOPATH/bin"
+    export ANDROID_HOME="$HOME/Library/Android/sdk"
+    export ANDROID_NDK_HOME="$ANDROID_HOME/ndk/23.1.7779620"
+    export PATH="$PATH:$ANDROID_HOME/emulator"
+    export PATH="$PATH:$ANDROID_HOME/platform-tools"
+    export JAVA_HOME="/Applications/Android Studio.app/Contents/jre/Contents/Home"
+
+Ubuntu:
+
+    export GOPATH="$HOME/go"
+    export PATH="$PATH:$GOPATH/bin"
+    export PATH="$PATH:/usr/local/go/bin"
+    export ANDROID_HOME="$HOME/Android/Sdk"
+    export ANDROID_NDK_HOME="$ANDROID_HOME/ndk/23.1.7779620"
+    export PATH="$PATH:$ANDROID_HOME/emulator"
+    export PATH="$PATH:$ANDROID_HOME/platform-tools"
+    export JAVA_HOME="/usr/local/android-studio/jre"
+    export PATH="$PATH:$JAVA_HOME/bin"
+
+In a terminal, enter:
+
+    git clone https://github.com/ipfs-shipyard/gomobile-ipfs
+    cd gomobile-ipfs/packages
+
+To build the core, enter:
+
+    make build_core.android
+
+Or you can make other Android targets which also build the core. See:
+
+    make help
+
+## Build for iOS (macOS only)
+
+Open a new terminal to get the setup from the installers. To set the environment
+variables, enter the following. (You must do this each time you start a new
+terminal, or put the commands in ~/.bash_profile.)
+
+    export GOPATH="$HOME/go"
+    export PATH="$PATH:$GOPATH/bin"
+
+In a terminal, enter:
+
+    git clone https://github.com/ipfs-shipyard/gomobile-ipfs
+    cd gomobile-ipfs/packages
+
+To build the core, enter:
+
+    make build_core.ios
+
+Or you can make other iOS targets which also build the core. See:
+
+    make help

README.md

@@ -24,7 +24,8 @@ You can check the packages documentation [here](https://ipfs-shipyard.github.io/
 
 ## Build
 
-TODO
+See the file
+[INSTALL.md](https://github.com/ipfs-shipyard/gomobile-ipfs/blob/master/INSTALL.md).
 
 ## Code example