unmount: add page (#12155)

* Unmount: add page

* Update pages/linux/unmount.md

Co-authored-by: Vitor Henrique <87824454+vitorhcl@users.noreply.github.com>

* Update pages/linux/unmount.md

Co-authored-by: Vitor Henrique <87824454+vitorhcl@users.noreply.github.com>

* Update pages/linux/unmount.md

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

---------

Co-authored-by: velox0 <72274796+Velox@users.noreply.github.com>
Co-authored-by: Vitor Henrique <87824454+vitorhcl@users.noreply.github.com>
Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

pages/linux/unmount.md

@@ -0,0 +1,8 @@
+# umount
+
+> The correct command is umount (u-mount).
+> More information: <https://manned.org/umount.8>.
+
+- View documentation for the correct command:
+
+`tldr umount`