fix Greek dead key terminator (Ω→α), enable CapsLock language switch, fix parser key resolution

- change Greek dead key terminator from Ω to α in all layout versions,
  matching the official EurKEY spec (closes #11)
- change dead key state name from "dead: Ω" to "dead: α" in v1.2/v1.3
- enable TICapsLockLanguageSwitchCapable in build script (closes #8)
- fix parser to resolve all key codes from base keyMapSets, not just
  codes in explicit layout entry ranges
- add per-version exceptions for newly-discovered v1.2/v1.4 differences
- add Karabiner-Elements docs section, known issues section to README
- add Windows spec installers for reference
- regenerate all parsed JSON specs with fixed parser

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -71,10 +71,24 @@ v2.0 renames all dead key states to their initializing key combination:
 | ⌥⇧6            | ˇ               |
 | ⌥7              | ˚               |
 | ⌥⇧7            | ¯               |
-| ⌥m              | Ω               |
+| ⌥m              | α               |
 | ⌥⇧m            | √               |
 | ⌥\              | ¬               |
 
+## Customization with Karabiner-Elements
+
+macOS `.keylayout` files cannot distinguish between the FN key and other modifiers, and cannot remap FN to act as a custom modifier. To use FN (or any other key) as an additional modifier layer, use [Karabiner-Elements](https://karabiner-elements.pqrs.org/):
+
+1. Install Karabiner-Elements.
+2. In **Simple Modifications**, remap `fn` to a modifier key (e.g., `right_option`).
+3. In **Complex Modifications**, add rules that map your desired key combinations to Unicode character outputs.
+
+[Hammerspoon](https://www.hammerspoon.org/) is an alternative for Lua-based automation but does not intercept keystrokes at the same level as Karabiner.
+
+## Known issues
+
+- **Icon not visible in keyboard switcher badge (macOS Sonoma/Sequoia):** The template icon (which adapts to light/dark mode) disappears in the input source switching badge attached to text fields. This is a macOS bug affecting third-party template icons — Apple's built-in layouts are not affected. Non-template icons work correctly but lose dark mode adaptation.
+
 ## Notes on Ukelele and template icons
 
 Template icons switch color with the system theme (dark/light). Ukelele's GUI checkbox for template icons does not save correctly — the `TISIconIsTemplate` flag must be set manually in `Info.plist`: