Add Climdex Days Above TmaxXF Dataset (#32)

* first ssp

* first ssp

* 4 ssps

* add 110 threshold

* remove colon in layer names

* improve layer nanmes

* test two colormaps

* test new legend

* update all legends

* add tmaxxf screenshot and remove template cmip6-tas files

* update all dataset descriptions

* add prose

* formatting

* content edits

* content edits

* content edits

* Change data description column division

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Co-authored-by: Slesa Adhikari <slesaad@gmail.com>