mysides: add page (#11347)

* add mysides

* tiny fixes

* fix minor formatting issues

pages/osx/mysides.md

@@ -0,0 +1,24 @@
+# mysides
+
+> Add, list and remove finder favorites.
+> More information: <https://github.com/mosen/mysides>.
+
+- List sidebar favorites:
+
+`mysides list`
+
+- Add a new item to the end of the sidebar favorites:
+
+`mysides add {{example}} {{file:///Users/Shared/example}}`
+
+- Remove an item by name:
+
+`mysides remove {{example}}`
+
+- Add the current directory to the sidebar:
+
+`mysides add $(basename $(pwd)) file:///$(pwd)`
+
+- Remove the current directory from the sidebar:
+
+`mysides remove $(basename $(pwd))`