Add Welsh language files

Another new language! It's based off of the old translator pack so
it'll need to be updated later. This commit also includes some fixes
to the originally submitted version, mainly:

- "2.0" and ".99" were broken by excel(?), now fixed
- Removed traces from extraneous rows and columns
- Small human errors

This includes the update received 2023-06-09.

desktop_version/lang/cy/meta.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<langmeta>
+    <active>1</active>
+
+    <!-- should be lowercase because menu style, and should be in the language itself -->
+    <nativename>cymraeg</nativename>
+
+    <!-- English translation by X -->
+    <credit>Cyfieithiad Cymraeg gan Morgan Roberts (ynchwarae)</credit>
+
+    <!-- On the language screen, hard limit 40 8x8 characters. Space/Z/V sets this as the language -->
+    <action_hint>Pwyso, Z, neu V i'w dewis</action_hint>
+
+    <!-- Same as above, but for a gamepad button (hard limit 40 8x8 characters) -->
+    <gamepad_hint>Press {button} to select</gamepad_hint>
+
+    <!-- Enable automatic word wrapping instead of having to manually insert newlines -->
+    <autowordwrap>1</autowordwrap>
+
+    <!-- Enable automatic full-caps display of selected menu options ([SELECTED] not selected) -->
+    <toupper>1</toupper>
+
+    <!-- When automatically uppercasing, map i to İ (for Turkish) -->
+    <toupper_i_dot>0</toupper_i_dot>
+
+    <!-- When automatically uppercasing, allow ~ to be used to stop the next letter from being uppercased (for Irish) -->
+    <toupper_lower_escape_char>0</toupper_lower_escape_char>
+
+    <!-- The indication that a certain menu option or button is selected -->
+    <menu_select>[ {label} ]</menu_select>
+    <menu_select_tight>[{label}]</menu_select_tight>
+
+    <!-- The filename of the font to use. For example, "font_cn" means font_cn.png and font_cn.fontmeta. -->
+    <font>font</font>
+</langmeta>