Bump simple-git and lint-staged

Removes [simple-git](https://github.com/steveukx/git-js/tree/HEAD/simple-git). It's no longer used after updating ancestor dependency [lint-staged](https://github.com/okonet/lint-staged). These dependencies need to be updated together.


Removes `simple-git`

Updates `lint-staged` from 8.2.1 to 13.1.0
- [Release notes](https://github.com/okonet/lint-staged/releases)
- [Commits](https://github.com/okonet/lint-staged/compare/v8.2.1...v13.1.0)

---
updated-dependencies:
- dependency-name: simple-git
  dependency-type: indirect
- dependency-name: lint-staged
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

css/content.css

@@ -104,6 +104,7 @@
 
 .content .twitter-tweet {
   width: auto !important;
+  margin: 0 auto;
 }
 
 .content .wp-caption {
@@ -146,6 +147,12 @@
   font-size: 0.8rem;
 }
 
+.content .wp-block-table {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+}
+
 .content figcaption {
   font-size: var(--size-body-extra-small);
   font-style: italic;
@@ -171,12 +178,8 @@
   }
 }
 
-.content th,
-.content tr,
 .content td {
-  border-width: 0 0 1px;
-  border-style: solid;
-  border-color: var(--color-dark-blue);
+  border: 1px solid var(--color-dark-blue);
   padding: var(--space-xs);
 }
 

package.json

@@ -47,7 +47,7 @@
     "imagemin-jpegtran": "^6.0.0",
     "imagemin-pngquant": "^7.0.0",
     "jest": "^26.1.0",
-    "lint-staged": "^8.2.1",
+    "lint-staged": "^13.1.0",
     "mysql": "^2.18.1",
     "nodemon": "^2.0.4",
     "npm-run-all": "^4.1.5",