[Documentation] Markdown improvements n to s (#13948)

Signed-off-by: Jerome Luckenbach <github@luckenba.ch>

bundles/org.openhab.binding.serialbutton/README.md

@@ -6,7 +6,7 @@ This is a binding for probably one of the simplest devices possible: A simple pu
 
 The binding defines a single thing type called `button`.
 
-A button requires the single configuration parameter `port`, which specifies the serial port that should be used. 
+A button requires the single configuration parameter `port`, which specifies the serial port that should be used.
 
 The only available channel is a `SYSTEM_RAWBUTTON` channel called `button`, which emits `PRESSED` events (no `RELEASED` events though) whenever data is available on the serial port (which will be read and discarded).
 
@@ -17,25 +17,25 @@ Using the default toggle profile, this means that you can use this channel to to
 
 demo.things:
 
-```
+```java
 serialbutton:button:mybutton "My Button" [ port="/dev/ttyS0" ]
 ```
 
 demo.items:
 
-```
+```java
 Switch MyLight { channel="serialbutton:button:mybutton:button" }
 ```
 
 _Note:_ This is a trigger channel, so you will most likely bind a second (state) channel to your item, which will control your physical light, so you might end up with the following, if you want to use your button with a Hue bulb:
 
-```
+```java
 Switch MyLight { channel="hue:0210:1:bulb1:color,serialbutton:button:mybutton:button" }
 ```
 
 demo.sitemap:
 
-```
+```perl
 sitemap demo label="Main Menu"
 {
     Frame {