title: Ka Table Header fixed position issue
body: <p>I am trying the <a href="https://komarovalexander.github.io/ka-table/#/class-component" rel="nofollow noreferrer">Ka table</a> , but in my local the headers are not fixed , if the number of rows is large enough and if I scroll down , the header also gets scrolled down, my requirement is to keep them fixed as in the demo. Any help would be appreciated</p>