Add content to format_metadata, different_tools and help

[hot007]

resolves #15 , resolves #16 , resolves #23

Addresses #24

Please review!
Need to check if anchor links work in different_tools page, too.

Thank you :)

[paolap]

I also made quite a lot of changes to different tools trying to test a different formatting and a lot more content but I haven't pushed them yet, so I might try to merge your branch locally with mine, it might take sometime though

[hot007]

Ah, sorry Paola :( Please feel free to override my changes where needed - or if it's not too disparate then you could accept this then merge. I suspect I've just caused you a pile of pain though, sorry I should have done it as multiple pull requests in hindsight :(
Also see new comment on #24 which you may have already addressed in your changes.

[hot007]

In hindsight we should definitely do one pull request per page!

[chloemackallah]

Love the braindump in format_metadata

[hot007]

I'm bad at maths - there's an error in format metadata where I estimate chunk size, it'll be out by a factor of 8 because I forgot that bits and bytes aren't the same thing :p so @chloemackallah that'll need to be fixed. I can do that on review but I'm not going to make any more edits until Paola's had a chance to deal with the mess I made her in the tools section.

[hot007]

Then realised I can change that file without affecting @paolap so I've fixed that chunk size estimate. Thanks heaps for the review Chloe! :)

[hot007]

DO NOT MERGE THIS PULL REQUEST!!!
It should not have gone to main branch. This PR is replaced by #27
Instead we should issue a PR to a branch on this repo and then merge branches.

[hot007]

I think I can merge this one too now. Apologies for the mess!