Fix typo in "Background" README section

Author: HorlogeSkynet

README.md

@@ -104,7 +104,7 @@ namely from these data sources (from high to low precedence):
 * The os-release file `/etc/os-release` if present, with a fall-back on `/usr/lib/os-release` if needed.
 * The output of the `lsb_release` command, if available.
 * The distro release file (`/etc/*(-|_)(release|version)`), if present.
-* The `uname` command for BSD based distrubtions.
+* The `uname` command for BSD based distributions.
 
 
 ## Python and Distribution Support