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.

README.md

@@ -99,7 +99,7 @@ use most:
 
 lazysecrets never stores, caches or sends your secret values. It keeps the
 names and metadata of what you've loaded in a cache file readable only by
-you, to show it at once next time (`cache: false` turns it off). It talks
+you, to show it at once next time (`storage.cache: false` turns it off). It talks
 only to the services you use it with, and collects no usage data. The one
 call of its own is a daily check for a new release, on GitHub or else
 git.kebcloud.no, which `updates.autoCheck: false` turns off.