Support for conditional printing

Syntax:
```
<% if(myBool) %>
Only printed if myBool == true
<% endif %>

<% if(myVar == 5) %>
Simple value checks
<% elif(myVar > 8) %>
Elif/Else Support, lower than/ greater than for ints and floats
<% else %>
[[Link to sth]]
<% endif %>
```

