fix: don't replace all the fonts with Lota Grotesque SemiBold (#1038)

The fix from #1037 worked way too well. This PR only applies the font to
the relevant `font-family`.


![obrazek](https://github.com/apify/apify-docs/assets/61918049/f3b08273-e096-4d29-aa89-9530b95f7aca)


(I actually kinda like the look of it, but it all probably shouldn't be
the same `font-weight`. I suppose the web team can deal with the design
question later).

Author: barjin

apify-docs-theme/src/theme/custom.css

@@ -339,90 +339,13 @@ body {
     line-height: 24px;
 }
 
-@font-face {
-    font-family: -apple-system;
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: BlinkMacSystemFont;
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Segoe UI';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Roboto';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Oxygen';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Ubuntu';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Cantarell';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Fira Sans';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Droid Sans';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
-@font-face {
-    font-family: 'Helvetica Neue';
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
 @font-face {
     font-family: 'Lota Grotesque';
     src: url('/font/lota.woff2') format('woff2'),
     url('/font/lota.woff') format('woff');
     font-weight: 600;
 }
 
-@font-face {
-    font-family: sans-serif;
-    src: url('/font/lota.woff2') format('woff2'),
-    url('/font/lota.woff') format('woff');
-    font-weight: 600;
-}
-
 .navbar__item {
     font-weight: 500;
 }