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[markrandall]

Self(ish) contained landing page.

Changes since earlier previews:

• Removed top set of navigation cards until we have more pages in place
• Swaps out elephpant logo for Levi's PHP logo
• Changed styling mechanism for light and dark mode using css selectors (not the toggle).
• Removed large buttons on every card, uses a combination of hover / select effects, with a top-right icon to indicate the whole card is clickable.
• Used javascript to dynamically resize cards in display: flex so non-full lines will center-align.

Areas I'm not quite happy with:

• Button focus styles.
• Need better responsiveness on the section header font sizes.
• Need to get something better for github logo or update ClickableCard renderer to allow directly injecting SVG.

Notes:

• Includes Add phpstan type to NewsHandler #1932 and [Preview - Part 1] Eliminate globals for $RELASES / $OLDRELEASES / $BRANCHES #1931
• Included an updated pregen-news.inc for newer events copied from prod - This accounts for the vast majority of the line count.