docker: create distinct containers for blockchains

Create disctinct containers for Litecoin and Bitcoin, and also change
the readme accordingly.

docker/ltcd/Dockerfile

@@ -14,7 +14,7 @@ EXPOSE 18555 18556
 # Expose segnet ports (server, rpc)
 EXPOSE 28901 28902
 
-# Grab and install the latest version of roasbeef's fork of btcd and all
+# Grab and install the latest version of roasbeef's fork of ltcd and all
 # related dependencies.
 WORKDIR $GOPATH/src/github.com/ltcsuite/ltcd
 RUN git clone https://github.com/ltcsuite/ltcd ./
@@ -25,12 +25,11 @@ RUN go install . ./cmd/ltcctl ./cmd/gencerts
 RUN mkdir "/rpc" "/root/.ltcd" "/root/.ltcctl"
 RUN touch "/root/.ltcd/ltcd.conf"
 
-# Manually generate certificate and add all domains, it is needed to connect
 # "ltcctl" and "lnd" to "ltcd" over docker links.
 RUN "/go/bin/gencerts" --host="*" --directory="/rpc" --force
 
 # Create a volume to house pregenerated RPC credentials. This will be
-# shared with any lnd, btcctl containers so they can securely query btcd's RPC
+# shared with any lnd, btcctl containers so they can securely query ltcd's RPC
 # server.
 # You should NOT do this before certificate generation!
 # Otherwise manually generated certificate will be overriden with shared