Make Linux instructions generic plus 32-bit cross-compile info

Author: chuckhoupt

README.md

@@ -39,12 +39,22 @@ Build Dependencies
 
 ### Linux
 
-Generally, a GNU/Linux OS with standard build tools (Make, GCC with 32-bit support), Git, Ruby, Libcurl, and Tcl/Tk. Packages for popular distributions:
+Generally, a GNU/Linux OS with standard build tools (Make, C-compiler, etc), Git, Ruby, Libcurl, and Tcl/Tk. Packages for popular distributions:
+
+Debian/Ubuntu: `sudo apt-get update && sudo apt-get install build-essential git gcc-multilib ruby ruby-dev php libcurl4-openssl-dev tk-dev`
+
+CentOS/Fedora: `sudo yum groupinstall 'Development Tools' && sudo yum install ruby ruby-dev php libcurl tcl-devel tcl tk-devel tk`
+
+<details>
+<summary>Packages for 32-bit cross compiling</summary>
 
 Debian/Ubuntu: `sudo dpkg --add-architecture i386 && sudo apt-get update && sudo apt-get install build-essential git gcc-multilib ruby ruby-dev php libcurl4-openssl-dev:i386 tk-dev:i386`
 
 CentOS/Fedora: `sudo yum groupinstall 'Development Tools' && sudo yum install ruby ruby-dev php glibc-devel.i686 libgcc.i686 libcurl.i686 tcl-devel.i686 tcl.i686 tk-devel.i686 tk.686`
 
+</details>
+
+
 ### Mac OS X
 
 [Xcode](https://developer.apple.com/xcode/) command line tools.