Update cheatsheets

tldr/linux/apptainer-run-help

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+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# apptainer run-help
+
+> Display user-defined help for an Apptainer container image.
+> Help text is defined in the `%help` section of the container's definition file.
+> More information: <https://apptainer.org/docs/user/main/cli/apptainer_run-help.html>.
+
+- Display help for a container:
+
+`apptainer run-help {{path/to/image.sif}}`
+
+- Display help for a specific app within a container:
+
+`apptainer run-help --app {{app_name}} {{path/to/image.sif}}`
+
+- Display help:
+
+`apptainer run-help {{[-h|--help]}}`