Issue273/README fixes and HTML stats

[mattloose]

This pull request addresses a number of issues (see commits).

All images are linked to the raw github urls to allow docs to propagate correctly.

[mattloose]

I also note I cannot spell the word brief.

[Adoni5]

PR now covers two additions to readfish.

Closes #273

1. HTML flag on stats

ReadfishSummarise 0.2.5 and by extension readfish stats outputs a HTML table of the summary via the use of an OPT IN flag --html <FILENAME>. This was added so we can embed a more readable table to the README.md

2. README updates

1. Readme images updated to Minknow 5.7.5
2. Link to 5khz R10 NA12878 bulk file added
3. Links to the image sin the main branch of ReadFish added
4. Example analysis output from readfish stats using the --html flag added to the analysing test output section.

[Adoni5]

Have been through the README, looks good. Once merged we should move refactor to main and have magic working images again.