fix: reject empty pages at construction (v0.1.1)

empty pages gave max_pages=0; get_page(0)/start() then IndexError'd on self.pages[0].
guard in __init__ with a clear ValueError instead of a deferred crash at render.

verified: ButtonPaginator([]) -> ValueError; non-empty and single-page intact.
Signed-off-by: disqualifier <dev@disqualifier.me>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "dpy_paginator"
-version = "0.1.0"
+version = "0.1.1"
 description = "Button-navigated paginator for discord.py — config-free, injectable emojis, installable."
 requires-python = ">=3.10"
 dependencies = [