I'm relatively new to pandoc and completely new to templates. I have already searched the documentation on pandoc.org and could not find much on templates per say, there is a great deal on different types of filters, but I am not sure what the difference is between templates and filters.

If the page's author and authored date are specified in the <head> tag, insert them on new lines below the page title
If there are <header>, <footer> or <nav> elements, those should be skipped and not included in the markdown file
If its possible to also skip parts of the input file according to their class or id attributes that would be great
If there is an <iframe> tag, say for an embedded video, a hyperlink to, or at least the value of, the src attribute should appear in place of the iframe
Insert the page's URL in the last line at the bottom of the markdown file

Thanks.