feat: config grouped by area, with per-provider timeouts and an update interval (#60)

Regroups the config, while there are no users to migrate:

- `ui`: icons, sourcesView, collapseGroups, loadDelay, expiryWarningDays
- `values`: revealTimeout, hideOnBlur, clipboardClear
- `storage`: cache, history
- `updates`: autoCheck (was updateCheck), autoCheckInterval (new, 24h by default), updateSources (was releases)
- `providers.timeout` (was timeout), plus `timeout` on azure, databricks and repos overriding it for that provider; `--timeout` still sets them all
- `sharing` (was share), in the config and in a repo's `.lazysecrets.yaml`

docs/config.md and the pages naming these keys are updated.

Reviewed-on: #60
Co-authored-by: Karl-Einar Bergstrøm <karl-einarb@outlook.com>

docs/repos.md

@@ -60,7 +60,7 @@ A repo's `.lazysecrets.yaml` can also name the secret its env files are
 [shared](links.md#sharing-env-files) with:
 
 ```yaml
-share:
+sharing:
   key: https://kv-team.vault.azure.net/secrets/env-share   # or its lazysecrets:// link
 ```