Add a Linux export preset.

export_presets.cfg

@@ -117,3 +117,29 @@ application/product_name="Foreigner Export Demo"
 application/file_description=""
 application/copyright=""
 application/trademarks=""
+
+[preset.3]
+
+name="Linux/X11"
+platform="Linux/X11"
+runnable=true
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="exports/linux/v0.1.0/ForeignerExportDemo-v0.1.0.x86_64"
+patch_list=PoolStringArray(  )
+script_export_mode=1
+script_encryption_key=""
+
+[preset.3.options]
+
+texture_format/bptc=false
+texture_format/s3tc=true
+texture_format/etc=false
+texture_format/etc2=false
+texture_format/no_bptc_fallbacks=true
+binary_format/64_bits=true
+binary_format/embed_pck=true
+custom_template/release=""
+custom_template/debug=""