implements a generic solution to redirect query strings generated by
forms to path based URIs that can be handled by existing routes.
This eliminates the need for javascript that was doing the equivalent
client-side.
Changes:
+ present not-found page for unhandled uri paths, eg /stuff
+ display the tip-height on front page
+ add favicon and neptune logo to front page
+ use ServerDir instead of ServeFile for /image and /css
+ add help tooltips for fields on front page
+ use monospace font for digests
Changes:
1. integrates pico minimal responsive css framework for light/dark
themes and overall better looks.
2. adds a not-found page for bad url queries.
3. catches axum/serde deserialization errors of user input and routes
them to the not-found page with a helpful hint (parse error msg)
