Make capturing more flexible by adding parameters to org-node-capture-target

This is a proposal to make capturing using `org-capture` a bit more flexible such that some use-cases that `org-roam-capture` allows can also be handled without extending `org-capture`. One such use-case is the ability to provide a directory in which a new file is to be generated per template. Currently, `org-node` works around this by allowing the user to configure whether she should be asked for the folder when a new file is created ... but it would be nicer if one could set specific folders for specific templates. This pull-request adds the possibility to provide a plist with parameters to `org-node-capture-template` for influencing the path for a new file. For usage in a capture template, In the result has to be wrapped in a nullary lambda function in the capture template: ~~~ elisp (function (lambda () (org-node-capture-target '(:path "~/org/articles")))) ~~~ (the change is backward compatible, i.e., `(function org-node-capture-target)` still works.) The following parameters exist: - `:path`: Provide the path of the directory in which the new file will be created - `:ask_path` Always ask for the path, even if `org-node-file-directory-ask` is configured otherwise Possibly, a few more use-cases could be tackled with this approach.