gimp: add page (#5399)

pages/common/gimp.md

@@ -0,0 +1,28 @@
+# gimp
+
+> An image manipulation and paint program.
+> More information: <https://docs.gimp.org/en/gimp-fire-up.html#gimp-concepts-running-command-line>.
+
+- Launch GIMP:
+
+`gimp`
+
+- Launch but don't show the splash screen:
+
+`gimp --no-splash`
+
+- Start a new instance, even if there is already a running one:
+
+`gimp --new-instance`
+
+- Open the given file as new image:
+
+`gimp --as-new {{path/to/image}}`
+
+- Print errors and warnings to the console, instead of showing them in a dialog box:
+
+`gimp --console-messages`
+
+- Enable debugging signal handlers:
+
+`gimp --debug-handlers`