How to create a content list

Hello

(I've tried to search the documentation but I can't seem to find what I am looking for, so hopefully you can direct me - as I am sure it must already exist.)

I would like the option to add a block to the start of my posts which lists out all the content as internal hyperlinks (giving me the option to use H2, H3, H4 headers. Where would I find such an option or what steps do I need to follow to make this happen.

Thanks in advance.