feat: config settings grouped under ui, values, storage and providers

icons, sourcesView, collapseGroups, loadDelay and expiryWarningDays move
under ui; revealTimeout, hideOnBlur and clipboardClear under values;
cache and history under storage; timeout under providers. share is now
sharing, in the config and in a repo's .lazysecrets.yaml.

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
 ```