Rebuild of OUHFT branch

[marshalc]

In an attempt to more closely track the modifications we've made to the upstream project for local needs, we're rebuilding our main tracking branch, but pulling out all the feature changes we've added into their own sub-branches so that we can more closely track their progress in the future.

This issue is going to be the parent ticket for these changes which will include:

1. Adding NHS Colour options + OUH Brandmark + related style changes
2. Implementing PageFind in place of the default JS search solution
3. Adding our local documentation pages
4. Adding our local Gitlab build templates
5. Image Gallery Short-code
6. Plotly Short-code

[marshalc]

This is happening following work related to google#1793 and where I made a bit of a mess to our current branch.

[marshalc]

The (smarter?) process will be to branch from the last "stable" release - https://github.com/google/docsy/tree/v0.8.0 - Implement our local changes via their own feature branches, and then play the latest main changes forward to bring the Head of ouhft to level with the current Head of main, fixing each feature branch as needed to accommodate the changing base and merging them in... then things might get a little messy again as we try to stay current.

[marshalc]

Initial branch setup:

• New clone of repo git clone https://github.com/ouhft/docsy.git ./docsy-repo
• cd docsy-repo
• Can't do git checkout -b ouhft tags/v0.8.0 as fatal: 'tags/v0.8.0' is not a commit and a branch 'ouhft' cannot be created from it. This is because this forking of the google project has not pulled any of the upstream tags across with it. Thus to achieve a new branch from the relevant commit, we need to do...
• git checkout -b ouhft 6bb4f99d1eab4976fb80d1488c81ba12b1715c05
• Then push up via git push --set-upstream origin ouhft

NB: at this time, live build processes are failing because of the loss of the CI Build Templates from this branch!

[marshalc]

First commit 03455fb used to rename the Hugo Module to be distinct from the upstream Google variant.

[marshalc]

As of 564bd1a (branch 0-8-0+nhs-colours) we have working primary colour selection. Colour choices: amber, blue (Default), brown, cyan, deep-orange, deep-purple, green, grey, indigo, light-blue, light-green, lime, orange, pink, purple, red, teal, & yellow.

[marshalc]

Excellent news, Docsy 0.9.0 has just been released, so that can be neatly wrapped up into this upgrade cycle!

Changes merged into ouhft branch at 47c9d95