The revive compiler documentation (#424)

This PR adds comprehensive project documentation in the form of an
mdBook.

---------

Signed-off-by: xermicus <cyrill@parity.io>
Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>
Co-authored-by: LJ <81748770+elle-j@users.noreply.github.com>
Co-authored-by: PG Herveou <pgherveou@gmail.com>

Makefile

@@ -10,6 +10,7 @@
 	format \
 	clippy \
 	doc \
+	book \
 	machete \
 	test \
 	test-integration \
@@ -18,6 +19,7 @@
 	test-workspace \
 	test-wasm \
 	test-llvm-builder \
+	test-book \
 	bench \
 	bench-pvm \
 	bench-evm \
@@ -59,11 +61,14 @@ clippy:
 doc:
 	cargo doc --all-features --workspace --document-private-items --no-deps
 
+book: test-book
+	mdbook serve book --open
+
 machete:
 	cargo install cargo-machete
 	cargo machete
 
-test: format clippy machete test-workspace install-revive-runner install-revive-explorer doc
+test: format clippy machete test-workspace install-revive-runner install-revive-explorer doc test-book
 
 test-integration: install-bin
 	cargo test --package revive-integration
@@ -84,6 +89,11 @@ test-llvm-builder:
 	@echo "warning: the llvm-builder tests will take many hours"
 	cargo test --package revive-llvm-builder -- --test-threads=1
 
+test-book:
+	cargo install mdbook --version 0.5.1 --locked
+	mdbook test book
+	mdbook build book
+
 bench: install-bin
 	cargo criterion --all --all-features --message-format=json \
 	| criterion-table > crates/benchmarks/BENCHMARKS.md
@@ -113,3 +123,4 @@ clean:
 	rm -rf crates/resolc/src/tests/cli/artifacts ; \
 	cargo uninstall resolc ; \
 	cargo uninstall revive-llvm-builder ;
+	mdbook clean book