chore(ckeditor): add Trilium changes into content CSS

packages/ckeditor5/src/theme/ck-content.css

@@ -0,0 +1,42 @@
+.printed-content .ck-widget__selection-handle, .printed-content .ck-widget__type-around { /* gets rid of triangles: https://github.com/zadam/trilium/issues/1129 */
+    display: none;
+}
+
+.page-break {
+    page-break-after: always;
+}
+
+.printed-content .page-break:after,
+.printed-content .page-break > * {
+    display: none !important;
+}
+
+.ck-content li p {
+    margin: 0 !important;
+}
+
+.admonition {
+    --accent-color: var(--card-border-color);
+    border: 1px solid var(--accent-color);
+    box-shadow: var(--card-box-shadow);
+    background: var(--card-background-color);
+    border-radius: 0.5em;
+    padding: 1em;
+    margin: 1.25em 0;
+    position: relative;
+    overflow: hidden;
+}
+
+.admonition p:last-child {
+    margin-bottom: 0;
+}
+
+.admonition p, h2 {
+    margin-top: 0;
+}
+
+.admonition.note { --accent-color: #69c7ff; }
+.admonition.tip { --accent-color: #40c025; }
+.admonition.important { --accent-color: #9839f7; }
+.admonition.caution { --accent-color: #ff2e2e; }
+.admonition.warning { --accent-color: #e2aa03; }