Flattened the structure of the knowledge base

knowledge base/rpm.md

@@ -0,0 +1,20 @@
+# The RPM package manager
+
+## TL;DR
+
+```shell
+# list all installed packages
+rpm --query --all
+
+# list files installed by a package
+rpm --query --list package
+
+# find the package owning a file
+rpm --query --file /usr/bin/file
+```
+
+## Further readings
+
+- [How can I list all files which have been installed by an ZYpp/Zypper package?]
+
+[how can i list all files which have been installed by an zypp/zypper package?]: https://unix.stackexchange.com/questions/162092/how-can-i-list-all-files-which-have-been-installed-by-an-zypp-zypper-package#239944