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>

book/src/faq.md

@@ -0,0 +1,28 @@
+# FAQ
+
+## What EVM version do you support?
+
+We neither do nor don't support any EVM version. We support Solidity versions, starting from `solc` version 0.8.0 onwards.
+
+## Is inline assembly supported
+
+Yes, almost all inline assembly features are supported ([see the differences in Yul translation chapter](user_guide/differences.md)).
+
+## Do you support opcode `XY`?
+
+See above, the same applies.
+
+## In what Solidity version should I write my dApp?
+
+We generally recommend to always use the latest supported version to profit from latest bugfixes, features and performance improvements.
+
+Find out about the latest supported version by running `resolc --supported-solc-versions` or checking [here](https://github.com/paritytech/resolc-bin).
+
+## Tool `XY` says the contract size is larger than 24kb and will fail to deploy?
+
+The 24kb code size restriction only exist for the EVM. Our limit is currently around 1mb and may increase further in the future.
+
+## Is `resolc` a drop-in replacement for `solc`?
+
+No. `resolc` aims to work similarly to `solc`, but it's not considered a drop-in replacement.
+