deps.edn: Bump dependencies

Update copyright years

README*: Add examples

Bump version to 0.9.5

deps.edn: Update tempura version

Rename config_example.yml to config-example.yml

"-example" seems more idiomatic than "_example" for this kind of
usage.  Thanks to Hélène Jonin for raising this.

Revert ".gitignore: Add config.yml"

This reverts commit bddab8d152e6cb79fdd15fd237f63eb54c0789ac.

README*: Update documentation

.gitignore: Add config.yml

config.yml -> config_example.yml

src/cljs/choices/core.cljs: Remove println leftover

src/cljs/choices/core.cljs: Compute max value for a score

Don't set the max value for a score manually: compute it from the
sum of possible positive increments of the value when the user go
through the choices.

src/cljs/choices/core.cljs: Fix bug

Allow to display scores in the final message as percentage

Score variables can now have a "max" value used to express the final
score value as a percentage.

Implement format strings for scores in the score final message

config.yml: Fix progress bar setup

Fix copyright headers

src/cljs/choices/core.cljs: Small syntactic fix

resources/public/css/choices.css: Update Bulma to 0.9.4

deps.edn: Bump reagent/reagent version

Also add cljsjs/react and cljsjs/react-dom as this is now required
since reagent 1.1.0.

See https://github.com/reagent-project/reagent/blob/master/CHANGELOG.md#110-2021-06-05