rpmspec: add page (#6779)

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Co-authored-by: Axel Navarro <navarroaxel@gmail.com>
Co-authored-by: pixel <chrissx@chrissx.de>
Co-authored-by: marchersimon <50295997+marchersimon@users.noreply.github.com>

pages/linux/rpmspec.md

@@ -0,0 +1,20 @@
+# rpmspec
+
+> Query a RPM spec file.
+> More information: <https://manned.org/rpmspec>.
+
+- List binary packages which would be generated from a rpm spec file:
+
+`rpmspec --query {{path/to/rpm.spec}}`
+
+- Get summary information for single binary packages generated from a rpm spec file:
+
+`rpmspec --query --queryformat "{{%{name}: %{summary}\n}}" {{path/to/rpm.spec}}`
+
+- Get the source package which would be generated from a rpm spec file:
+
+`rpmspec --query --srpm {{path/to/rpm.spec}}`
+
+- Parse a rpm spec file to `stdout`:
+
+`rpmspec --parse {{path/to/rpm.spec}}`