### Godot version

3.5.1.stable, v4.0.beta.custom_build [0a87ead64]

### System information

Ubuntu 22.04.1

### Issue description

For example, if project has name "300spartans", we can't enter the "org.godotengine.300spartans" to "Unique Name" field. We get the error "Invalid package name: A digit cannot be the first character in a package segment". But , if we enter "org.godotengine.$genname", there will be no error message. When exporting, the name will be set as "org.godotengine.spartans" without "300" in beginning, but user will not be informed about it. I think, it is not very good. It may not be worth making changes to the source code, but mention it in the documentation.

### Steps to reproduce

See issue description.

### Minimal reproduction project

N/A
/*
	 *  By not compressing files with little or no benefit in doing so,
	 *  a performance gain is expected at runtime. Moreover, if the APK is
	 *  zip-aligned, assets stored as they are can be efficiently read by
	 *  Android by memory-mapping them.
	 */
	
	static const char *unconditional_compress_ext[] = {
		
		
		".jpg", ".jpeg", ".png", ".gif",
		".wav", ".mp2", ".mp3", ".ogg", ".aac",
		".mpg", ".mpeg", ".mid", ".midi", ".smf", ".jet",
		".rtttl", ".imy", ".xmf", ".mp4", ".m4a",
		".m4v", ".3gp", ".3gpp", ".3g2", ".3gpp2",
		".amr", ".awb", ".wma", ".wmv",
		
		".webp", 
		".cfb", 
		".scn", 
		".ctex",