wiki: remove hidden example configs from navigation
Only baseline (config.lua) and tiling remain as tracked examples.
Deleted walkthrough pages: Freeform-Move, Snap-Grid, Clump, Nested-Debug, TTY-Baseline.
Updated all overviews, sidebars, and guides to reference only the 2 remaining examples.
Shared helpers page (common.lua, rules.lua) is kept.
Make imperative Lua style the default in wiki guides
- switch major config-writing and hooks docs to show imperative runtime
commands first
- document returned actions as an alternative style instead of the default
- add the imperative evil.spawn helper to the command-oriented docs