docs: misc cleanups/changes

Author: fanquake

README.md

@@ -15,9 +15,9 @@ fixed.
 
 ## Quick start
 
-Requires that [Docker be installed](https://docs.docker.com/engine/installation/) on the host machine.
+Requires that [Docker be installed](https://docs.docker.com/install/) on the host machine.
 
-```
+```bash
 # Create some directory where your bitcoin data will be stored.
 $ mkdir /home/youruser/bitcoin_data
 
@@ -65,7 +65,7 @@ restart
 policies](https://docs.docker.com/config/containers/start-containers-automatically/#use-a-restart-policy),
 but if you're insistent on using systemd, you could do something like
 
-```
+```bash
 $ cat /etc/systemd/system/bitcoind.service
 
 # bitcoind.service #######################################################################

bin/docker_entrypoint.sh

@@ -14,7 +14,7 @@ if [ ! -e "${BITCOIN_CONF}" ]; then
 # For documentation on the config file, see
 #
 # the bitcoin source:
-#   https://github.com/bitcoin/bitcoin/blob/master/contrib/debian/examples/bitcoin.conf
+#   https://github.com/bitcoin/bitcoin/blob/master/share/examples/bitcoin.conf
 # the wiki:
 #   https://en.bitcoin.it/wiki/Running_Bitcoin
 
@@ -44,8 +44,14 @@ disablewallet=${BTC_DISABLEWALLET:-1}
 # Enable an on-disk txn index. Allows use of getrawtransaction for txns not in
 # mempool.
 txindex=${BTC_TXINDEX:-0}
+
+# Run on the test network instead of the real bitcoin network.
 testnet=${BTC_TESTNET:-0}
+
+# Set database cache size in MiB
 dbcache=${BTC_DBCACHE:-512}
+
+# ZeroMQ notification options:
 zmqpubrawblock=${BTC_ZMQPUBRAWBLOCK:-tcp://0.0.0.0:28333}
 zmqpubrawtx=${BTC_ZMQPUBRAWTX:-tcp://0.0.0.0:28333}
 zmqpubhashtx=${BTC_ZMQPUBHASHTX:-tcp://0.0.0.0:28333}