Move pages under tldr, lint run.sh, update docs

tldr/linux/mountpoint

@@ -0,0 +1,21 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# mountpoint
+
+> Test if a directory is a filesystem mountpoint.
+> More information: <https://manned.org/mountpoint>.
+
+- Check if a directory is a mountpoint:
+
+`mountpoint {{path/to/directory}}`
+
+- Check if a directory is a mountpoint without showing any output:
+
+`mountpoint -q {{path/to/directory}}`
+
+- Show major/minor numbers of a mountpoint's filesystem:
+
+`mountpoint --fs-devno {{path/to/directory}}`