elytra pitch helper

this brings 2.1.0 support for 26.2 snapshot 8 and maybe higher

• added config screen. you can open it with keybind (no by default), or via Mod Menu if it is installed.
• added profile support. you can create, rename, duplicate, edit, sort, and delete different eph configs.
• added a new turn-timing cue that can help with dive/climb rhythm using height, velocity, or either one.
• added settings for guide line length and thickness.
• added a third-person toggle so guides can be shown outside first person if enabled.
• added profile JSON opening from the config screen for manual editing.
• cleaned up guide rendering and removed the old center tick marker.
• updated mod icon.