yadm: add pages (#13920)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/common/yadm-encrypt.md

@@ -0,0 +1,13 @@
+# yadm-encrypt
+
+> Encrypt files listed in the designated encrypt file.
+> After the files are encrypted they will be save in the designated archive folder.
+> More information: <https://yadm.io/docs/encryption>.
+
+- Encrypt files listed in the designated encrypt file:
+
+`yadm encrypt`
+
+- Create the necessary files and folders for encryption:
+
+`touch {{path/to/encrypt_file}} && mkdir {{path/to/archive_folder}}`