handlr: add page (#9922)

pages/linux/handlr.md

@@ -0,0 +1,28 @@
+# handlr
+
+> Manage your default applications.
+> More information: <https://github.com/chmln/handlr>.
+
+- Open a URL in the default application:
+
+`handlr open {{https://example.com}}`
+
+- Open a PDF in the default PDF viewer:
+
+`handlr open {{path/to/file.pdf}}`
+
+- Set imv as the default application for PNG files:
+
+`handlr set {{.png}} {{imv.desktop}}`
+
+- Set MPV as the default application for all audio files:
+
+`handlr set {{'audio/*'}} {{mpv.desktop}}`
+
+- List all default apps:
+
+`handlr list`
+
+- Print the default application for PNG files:
+
+`handlr get {{.png}}`