public final List<ResourceFile> getExtensionInstallationDirs() {
		return extensionInstallationDirs;
	}
Returns a prioritized {@link List ordered list} of the application Extensions installation 
directories.   Typically, the values may be any of the following locations:<br>
<ul>
<li><code>[user settings dir]/Extensions</code></li>
<li><code>[application install dir]/Ghidra/Extensions</code> (Release Mode)</li>
<li><code>ghidra/Ghidra/Extensions</code> (Development Mode)</li>
</ul>

@return an {@link List ordered list} of the application Extensions installation directories.
  Could be empty if the {@link ApplicationLayout} does not support application Extensions.
Ghidra/Framework/Utility/src/main/java/utility/application/ApplicationLayout.java