Refactor styles and update HTML structure for "Historia Firmy" and "O Nas" pages

- Removed commented-out flex property in historia-firmy.scss for active class.
- Added overflow hidden to main-page class in o-nas.scss.
- Adjusted heights for responsive design in o-nas.scss.
- Introduced gradient background for _col-1 in o-nas.scss.
- Updated margin and height properties for various elements in o-nas.scss.
- Removed unnecessary after pseudo-element in o-nas.scss.
- Added feedback slider component in o-nas.php with customer testimonials.
- Updated video element in o-nas.php to include controls and loop attributes.
- Commented out unused sections in o-nas.php for better clarity.
- Implemented Swiper functionality for feedback slider in o-nas.php.

layout/style-scss/historia-firmy.scss

@@ -75,7 +75,6 @@
 
 							&.active {
 								flex: 0 0 calc((100% / 8) * 2);
-								// flex: 0 0 200px;
 
 								@include respond-below(lg) {
 									flex: 0 0 calc((100% / 6) * 2);