secret-tool: add page (#13728)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/linux/secret-tool.md

@@ -0,0 +1,21 @@
+# secret-tool
+
+> Store and retrieve passwords, part of the `libsecret` package.
+> Communicates with Freedesktop secret service implementations such as `gnome-keyring`.
+> More information: <https://gnome.pages.gitlab.gnome.org/libsecret/>.
+
+- Store a secret with an optional label:
+
+`secret-tool store --label={{label}} {{key}} {{value}}`
+
+- Retrieve a secret:
+
+`secret-tool lookup key {{key}}`
+
+- Get more information about a secret:
+
+`secret-tool search key {{key}}`
+
+- Delete a stored secret:
+
+`secret-tool clear key {{key}}`