added katex package and import

package.json

@@ -76,6 +76,7 @@
     "highlight.js": "^10.1.2",
     "html-entities": "^1.3.1",
     "is-ip": "^2.0.0",
+    "katex": "^0.12.0",
     "linkifyjs": "^2.1.9",
     "lodash": "^4.17.19",
     "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#develop",

src/HtmlUtils.tsx

@@ -26,6 +26,7 @@ import _linkifyString from 'linkifyjs/string';
 import classNames from 'classnames';
 import EMOJIBASE_REGEX from 'emojibase-regex';
 import url from 'url';
+import katex from 'katex';
 
 import {MatrixClientPeg} from './MatrixClientPeg';
 import {tryTransformPermalinkToLocalHref} from "./utils/permalinks/Permalinks";

yarn.lock

@@ -5607,6 +5607,13 @@ jsx-ast-utils@^2.4.1:
     array-includes "^3.1.1"
     object.assign "^4.1.0"
 
+katex@^0.12.0:
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/katex/-/katex-0.12.0.tgz#2fb1c665dbd2b043edcf8a1f5c555f46beaa0cb9"
+  integrity sha512-y+8btoc/CK70XqcHqjxiGWBOeIL8upbS0peTPXTvgrh21n1RiWWcIpSWM+4uXq+IAgNh9YYQWdc7LVDPDAEEAg==
+  dependencies:
+    commander "^2.19.0"
+
 kind-of@^3.0.2, kind-of@^3.0.3, kind-of@^3.2.0:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-3.2.2.tgz#31ea21a734bab9bbb0f32466d893aea51e4a3c64"