Docs: rename 'How-to' section to 'Guides'

Signed-off-by: VirtualTam <virtualtam@flibidi.net>

index.php

@@ -1103,7 +1103,7 @@ function renderPage($conf, $pluginManager, $LINKSDB, $history, $sessionManager,
         // Linkdate is kept here to:
         //   - use the same permalink for notes as they're displayed when creating them
         //   - let users hack creation date of their posts
-        //     See: https://shaarli.readthedocs.io/en/master/Various-hacks/#changing-the-timestamp-for-a-shaare
+        //     See: https://shaarli.readthedocs.io/en/master/guides/various-hacks/#changing-the-timestamp-for-a-shaare
         $linkdate = escape($_POST['lf_linkdate']);
         if (isset($LINKSDB[$id])) {
             // Edit

mkdocs.yml

@@ -27,9 +27,9 @@ pages:
     - RSS feeds: RSS-feeds.md
     - REST API: REST-API.md
     - Community & Related software: Community-&-Related-software.md
-- How To:
+- Guides:
-    - Backup, restore, import and export: Backup,-restore,-import-and-export.md
+    - Backup, restore, import and export: guides/backup-restore-import-export.md
-    - Various hacks: Various-hacks.md
+    - Various hacks: guides/various-hacks.md
 - Development:
     - Development guidelines: Development-guidelines.md
     - Continuous integration tools: Continuous-integration-tools.md