docs: add blink-cmp-luasnip-choice community source (#2332)

Author: becknik

doc/configuration/sources.md

@@ -127,3 +127,4 @@ See [blink.compat](https://github.com/Saghen/blink.compat) for using `nvim-cmp`
 - [blink-cmp-vsnip](https://codeberg.org/FelipeLema/blink-cmp-vsnip)
 - [blink-cmp-dat-word](https://github.com/xieyonn/blink-cmp-dat-word): Word completion
 - [blink-cmp-dap](https://github.com/mayromr/blink-cmp-dap): Completions for DAP repl
+- [blink-cmp-luasnip-choice](https://github.com/becknik/blink-cmp-luasnip-choice): (LuaSnip)[https://github.com/L3MON4D3/LuaSnip] choice node completion