Updates and checking of user manual

As someone supporting IBEX I want the user manual to be as up to date as possible so that it is useful to those that need it.

As part of a Friday/Tech Debt day, this was started with the following completed and noted:

Sections reviewed and updated:
- [x] What Is IBEX - simplified the first page, moved the SECI comparison to a new page
- [x] Getting Help / Reporting Problems - no changes link takes you to the right bit of the FAQ, consider this there
- [x] Installing IBEX - Gutted a lot of the detail that was on this page (including full paths to directories...) this will need a rethink as to how we make the client available for download
- [x] Starting And Stopping IBEX - simplified to match the current situation on instruments
- [x] Key Concepts in IBEX - updated EPICS link
- [x] Instrument Specific Guidance - these seemed OK to me, at least what is there is OK
- [x] The Web Dashboard - seemed fine to me
- [x] FAQ Including scripting - only bit that really needed updating was the guidance on where to look for what is being worked on
- [x] Glossary - mostly OK, just the DAE description

Sections to be reviewed:
- [ ] IBEX GUI Features - needs new images, the extra behaviours adding
- [ ] How To Do Things In IBEX - needs new images, and I think by now it is missing quite a few routes through
- [ ] Scripting - feels like it is more out of date than it ought to be, need to remove the python 2 aspects
- [ ] The IBEX Script Generator
- [ ] Device Specific Guidance - There is some extra info needed on the Eurotherm, need to check about the FZJ choppers, the matplotlib is beyond my knowledge off the top of my head, otherwise I think everything looked OK, and the Reflectometry section had been updated by NR in November 2022, so should be fairly close to accurate
- [ ] Python-3 - Whether or not this is still needed would be best verified by someone else, as I'm not sure it is

Other things to consider/do in the future:
- [ ] Detail the need for a rethink of what we make available for download, and how we make them available
- [ ] Remove the notes regarding switching to and from SECI from the starting and stopping section of the IBEX manual
- [ ] Create advance PI planning boards for a few years (e.g. each of the PIs to the end of the IBEX project, plus a few more, this will allow notes of things that need to be done before/after big projects to be noted)
[ ] @FreddieAkeroyd to update the DAE section on Key Concepts in IBEX (https://github.com/ISISComputingGroup/ibex_user_manual/wiki/Key-Concepts-in-IBEX#id10) and in the glossary (https://github.com/ISISComputingGroup/ibex_user_manual/wiki/Glossary). Whilst those read true for DAE2, DAE3 does something different, and there is a very high chance that the Endeavour instruments will do something different again
[ ] Add a note to a future PI (once it is possible) to update the Scripting page to de-emphasize conversions from open genie to genie_python once IBEX is done
[ ] Update the Eurotherm guidance on https://github.com/ISISComputingGroup/ibex_user_manual/wiki/Eurotherm as it should probably reference the file format and information to help understanding for the calibration files too
[ ] @davidkeymer to check that https://github.com/ISISComputingGroup/ibex_user_manual/wiki/FZJ-Fermi-Chopper is still valid and reading appropriately
[ ] Look at the matplotlib guidance (https://github.com/ISISComputingGroup/ibex_user_manual/wiki/Matplotlib) to make sure that is still valid