use default 14px and override it for file-view

Author: silverwind

web_src/css/markup/content.css

@@ -1,6 +1,6 @@
 .markup {
   overflow: hidden;
-  font-size: 16px;
+  font-size: 14px;
   line-height: 1.5 !important;
   overflow-wrap: break-word;
 }
@@ -318,6 +318,7 @@ In markup content, we always use bottom margin for all elements */
 
 .file-view.markup {
   padding: 1em 2em;
+  font-size: 16px;
 }
 
 .file-view.markup:has(.file-not-rendered-prompt) {

web_src/css/repo.css

@@ -300,13 +300,6 @@ td .commit-summary {
   min-width: 100px;
 }
 
-.repository.new.issue .comment.form .content .markup,
-.repository.compare.pull .markup,
-.repository.view.issue .comment-list .comment .markup,
-.conversation-holder .markup {
-  font-size: 14px;
-}
-
 .repository.view.issue .instruct-toggle {
   display: inline-block;
 }