[docs] Add documentation on compiling FreeType on an Android Device

docs/.gitignore

@@ -12,6 +12,7 @@ reference/
 !INSTALL_MAC.md
 !INSTALL_UNIX.md
 !INSTALL_VMS.md
+!INSTALL_ANDROID.md
 !MODIFYING.md
 
 # MkDocs Config file

docs/INSTALL_ANDROID.md

@@ -0,0 +1,85 @@
+# Compiling FreeType on Android using Termux
+
+If you want to test FreeType on arm devices, compiling it on an Android
+phone is one of the easiest ways.
+
+## 1. Compiling FreeType
+
+1. Install and open termux
+
+2. Update termux packages using:
+
+   ```bash
+   pkg update
+   pkg upgrade
+   ```
+   Select `y` if any configuration changes are asked
+
+3. Install `git`:
+
+   ```bash
+   pkg install git
+   ```
+4. Install packages required for compilation:
+
+   ```bash
+   pkg install automake autoconf libtool make clang binutils
+   ```
+
+5. Clone FreeType's git repository:
+
+   ```bash
+   git clone https://gitlab.freedesktop.org/freetype/freetype.git
+   ```
+
+6. Enter into the source directory:
+
+   ```
+   cd freetype/
+   ```
+
+7. Now you can compile FreeType according to [INSTALL_UNIX.md]:
+
+   ```bash
+   ./autogen.sh
+   ./configure
+   make -j$(nproc)
+   ```
+   The compiled binaries can be accessed under `objs/.libs`
+
+## 2. Compiling FreeType Demo programs
+If you need to test your changes you may want to use ft-demo
+programs. They can be compiled and run by follwing these steps:
+
+1. First compile FreeType using the steps above.
+
+2. Clone FreeType demos adjacent to the `freetype/` directory:
+
+   ```bash
+   git clone https://gitlab.freedesktop.org/freetype/freetype-demos.git
+   ```
+   i.e. If you can access FreeType repo under `~/freetype`, you should
+   be able to access `~/freetype-demos`.
+
+3. Enter into the ft-demos directory:
+
+   ```bash
+   cd freetype-demos
+   ```
+
+4. Compile the programs:
+
+   ```bash
+   make
+   ```
+
+5. The compiled binaries can be accessed and executed under `bin/` like:
+
+   ```bash
+   cd bin
+   ./ftlint
+   ```
+
+<!---->
+
+[INSTALL_UNIX.md]: ./INSTALL_UNIX.md