Add liqtest test script readme

ts/client/scripts/liqtest/README.md

@@ -0,0 +1,50 @@
+### Set environment variables
+
+```
+CLUSTER=devnet
+CLUSTER_URL=https://mango.devnet.rpcpool.com/<token>
+PAYER_KEYPAIR=~/.config/solana/mb-liqtest.json
+# Adjust this to a free group
+GROUP_NUM=200
+```
+
+### Create tokens and markets
+
+This is one-time setup:
+```
+yarn ts-node ts/client/scripts/liqtest/liqtest-create-tokens-and-markets.ts
+```
+It'll emit some MINTS=... and SERUM_MARKETS=.. env vars, set those, all further
+commands will use them.
+
+### Make a group
+
+```
+yarn ts-node ts/client/scripts/liqtest/liqtest-create-group.ts
+```
+
+Groups can be reused a lot, but sometimes closing them may be necessary
+```
+yarn ts-node ts/client/scripts/liqtest/liqtest-close-group.ts
+```
+
+Preferably close all mango accounts first.
+
+### Create candidate mango accounts
+
+```
+yarn ts-node ts/client/scripts/liqtest/liqtest-make-candidates.ts
+```
+
+This creates a bunch of to-be-liquidated accounts as well as a LIQOR account.
+
+### Liquidate
+
+Run the liquidator on the group with the liqor account.
+
+### Settle and close all open mango accounts
+
+At any point, to reset by closing all accounts:
+```
+yarn ts-node ts/client/scripts/liqtest/liqtest-settle-and-close-all.ts
+```