improved markdown files + added markdownlint config

.markdownlint.yaml

@@ -0,0 +1,3 @@
+default: true
+single-title: false
+line-length: false

examples/README.md

@@ -3,14 +3,16 @@
 The simplest example are in `examples/simple.lua` file.
 
 It's performing all basic MQTT actions:
+
 1. connecting to broker
 2. subscribing to topic
 3. publishing message after subscription creation
 4. receiving self-published message
 5. disconnecting from MQTT broker
 
 Here is an expected output of such script:
-```
+
+```console
 created MQTT client     mqtt.client{id="luamqtt-v2-0-0-5807dc7"}
 running ioloop for it
 connected:      CONNACK{rc=0, sp=false, type=2}

examples/last-will/README.md

@@ -15,15 +15,15 @@ To reproduce you have to start `client-1.lua` and then `client-2.lua`.
 
 Here is an example output of both scripts:
 
-```
+```console
 $ lua examples/last-will/client-1.lua
 connected:      CONNACK{rc=0, type=2, sp=false}
 subscribed to luamqtt/close, waiting for connection close command from client-2
 received:       PUBLISH{qos=1, retain=false, topic="luamqtt/close", payload="Dear client-1, please close your connection", packet_id=1, type=3, dup=false}
 closing connection without DISCONNECT and stopping client-1
 ```
 
-```
+```console
 $ lua examples/last-will/client-2.lua
 connected:      CONNACK{rc=0, sp=false, type=2}
 subscribed to luamqtt/lost

openwrt/README.md

@@ -1,6 +1,6 @@
 # Building a package for OpenWRT
 
-You may build a package with luamqtt library in a standard way, like described here: https://openwrt.org/docs/guide-developer/helloworld/start
+You may build a package with luamqtt library in a standard way, like described here: <https://openwrt.org/docs/guide-developer/helloworld/start>
 
 But luamqtt is written in pure-lua, so you actually don't have to compile anything, only files should be packed correctly.