Project board improvements (#15429)

* Project board improvements

- Fix link colors
- Extract CSS to own file
- Various minor tweaks to make it look better

Fixes: https://github.com/go-gitea/gitea/issues/15424
Fixes: https://github.com/go-gitea/gitea/issues/15506
Fixes: https://github.com/go-gitea/gitea/pull/15511

* fix squashed cards on small view area

* more css fixes, add second row from issue list

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/js/features/projects.js

@@ -14,6 +14,7 @@ export default async function initProject() {
       group: 'board-column',
       draggable: '.board-column',
       animation: 150,
+      ghostClass: 'card-ghost',
       onSort: () => {
         const board = document.getElementsByClassName('board')[0];
         const boardColumns = board.getElementsByClassName('board-column');
@@ -42,6 +43,7 @@ export default async function initProject() {
       {
         group: 'shared',
         animation: 150,
+        ghostClass: 'card-ghost',
         onAdd: (e) => {
           $.ajax(`${e.to.dataset.url}/${e.item.dataset.issue}`, {
             headers: {