Change docs to use plural flags in kedro run suggestions and examples

[AhdraMeraliQB]

Description

Prerequisites: #2243 and #2244

We are switching over to using plural flags to replace --node, --tag, and --load-version. These changes should also be reflected in the docs wherever we give examples of using these flags.

Additionally, the use of these plural flags affects the docs on using config.yml for kedro runs: nodes and tags will no longer take lists, instead they should take comma separated arguments. See #1792 (comment) for further context. As a result, https://kedro.readthedocs.io/en/stable/kedro_project_setup/configuration.html#configure-kedro-run-arguments should also be updated under this ticket.

[AhdraMeraliQB]

Note: The table of commands on the docs page https://kedro.readthedocs.io/en/stable/development/commands_reference.html#modifying-a-kedro-run has a column titled "Multiple instances allowed?". This should be removed as no commands will have multiple instances allowed anymore, making this column redundant.

The column has been removed (see this comment) so the edit here would now be to delete the extra sentence "Multiple instances allowed" from the relevant decriptions.