document canvas, cairo, and dom renderer flags

Author: joshtynjala

_docs/advanced-setup/html5.md

@@ -80,6 +80,22 @@ Some Haxe externs support Lime out of the box, like [haxe-simple-peer](https://g
 
 The `<config:html5 />` element in your [_project.xml_](../../project-files/xml-format/) file is used to specify advanced configuration options for HTML/JS. For a complete list of these advanced option, see [Config Values: HTML5](../../project-files/xml-format/config/#html5).
 
+### Canvas rendering
+
+To force software rendering with HTML Canvas instead of WebGL, add the `-Dcanvas` option to your build command.
+
+```sh
+lime build html5 -Dcanvas
+```
+
+### DOM rendering
+
+To force rendering with the HTML DOM instead of WebGL, add the `-Ddom` option to your build command.
+
+```sh
+lime build html5 -Ddom
+```
+
 ## Help & Forums
 
 If you encounter any problems when setting up Lime for HTML5, please visit the [community forums](http://community.openfl.org/c/help) or our [Discord server](https://discord.gg/tDgq8EE).

_docs/advanced-setup/linux.md

@@ -30,6 +30,14 @@ To compile and launch a Linux executable with one command, run `lime test linux`
 
 The `<config:cpp />` element in your [_project.xml_](../../project-files/xml-format/) file is used to specify advanced configuration options for C++. For a complete list of these advanced option, see [Config Values: C++](../../project-files/xml-format/config/#c).
 
+### Cairo rendering
+
+To force software rendering with Cairo instead of OpenGL, add the `-Dcairo` option to your build command.
+
+```sh
+lime build linux -Dcairo
+```
+
 ## Help & Forums
 
 If you encounter problems setting up Lime to compile on Linux, please visit the [community forums](http://community.openfl.org/c/help) or our [Discord server](https://discord.gg/tDgq8EE).

_docs/advanced-setup/macos.md

@@ -28,6 +28,14 @@ To compile and launch a macOS _.app_ file with one command, run `lime test mac`.
 
 The `<config:cpp />` element in your [_project.xml_](../../project-files/xml-format/) file is used to specify advanced configuration options for C++. For a complete list of these advanced option, see [Config Values: C++](../../project-files/xml-format/config/#c).
 
+### Cairo rendering
+
+To force software rendering with Cairo instead of OpenGL, add the `-Dcairo` option to your build command.
+
+```sh
+lime build mac -Dcairo
+```
+
 ## Help & Forums
 
 You should not need to install the Xcode command-line tools. If this is not the case, or if you encounter other problems when setting up Lime for macOS, please visit the [community forums](http://community.openfl.org/c/help) or our [Discord server](https://discord.gg/tDgq8EE).

_docs/advanced-setup/windows.md

@@ -28,6 +28,14 @@ To compile and launch a Windows _.exe_ file with one command, run `lime test win
 
 The `<config:cpp />` element in your [_project.xml_](../../project-files/xml-format/) file is used to specify advanced configuration options for C++. For a complete list of these advanced option, see [Config Values: C++](../../project-files/xml-format/config/#c).
 
+### Cairo rendering
+
+To force software rendering with Cairo instead of OpenGL, add the `-Dcairo` option to your build command.
+
+```sh
+lime build windows -Dcairo
+```
+
 ## Help & Forums
 
 If you encounter any problems when setting up Lime for targeting Windows, please visit the [community forums](http://community.openfl.org/c/help) or our [Discord server](https://discord.gg/tDgq8EE).