Closes#5
Addresses #6
changes:
* field Mining Reward --> Coinbase. (actual reward)
* add field Expected Coinbase (expected/calced reward)
this field only displays if different from actual coinbase.
* add field Cumulative Proof-of-Work
* change tooltip 🛈 --> ⓘ . for mobile devices. (hopefully)
* css: make tooltip text bold, so the ⓘ is stronger.
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)
