liquidator docs (#512)

* liquidator docs

Signed-off-by: microwavedcola1 <microwavedcola@gmail.com>

* update

Signed-off-by: microwavedcola1 <microwavedcola@gmail.com>

* update

Signed-off-by: microwavedcola1 <microwavedcola@gmail.com>

---------

Signed-off-by: microwavedcola1 <microwavedcola@gmail.com>

bin/liquidator/README.md

@@ -0,0 +1,28 @@
+Two branches are relevant here:
+
+- `devnet`: bleeding edge, may be unstable, could be incompatible with deployed program
+- `main`: stable, currently running on the `mainnet-beta` cluster
+
+## Setup Environment
+
+### .env Config file:
+
+A `.env` file can be used to configure the liquidator setup. See `.env.example` for a example.
+
+The environment variables required are
+
+- `LIQOR_MANGO_ACCOUNT` - public key of the mango account
+- `LIQOR_OWNER` - private key of the owner of the mango account
+- `RPC_URL` - RPC cluster url
+- `SERUM_PROGRAM` - the Openbook program Id the mango group is configured with e.g. primary mango group `78b8f4cGCwmZ9ysPFMWLaLTkkaYnUjwMJYStWe5RTSSX` is configured to work with `srmqPvymJeFKQ4zGQed1GFppgkRHL9kaELCbyksJtPX`
+
+more advanced parameters
+
+- `MIN_HEALTH_RATIO` - minimum health ratio the liquidator should retain (default 50%)
+- `REBALANCE_SLIPPAGE_BPS` - slippage liquidator should tolerate when offloading tokens (default 100)
+
+```shell
+cargo run --bin liquidator
+```
+
+There is also a dockerfile `Dockerfile.liquidator` available in case one wants to run this in a containerized environment.