fix(docs-infra): fix code inside anchor elements with external URLs (#41694)

Previously, due to the `inline-flex` display style of anchor elements
with external URLs, `<code>` elements nested inside such anchor elements
would cause extra spacing between lines. An occurrence of this can be
seen in the [Angular workspace configuration][1] guide.

This commit fixes the problem by removing the `inline-flex` display
style (allowing anchor elements to fall back to the default `inline`
style).

For reference, the `inline-flex` style was introduced in commit
7944ee2c30c1f09219e152a4a1b2c5e51dd2c9c4 in order to avoid underlining
link icons. This style seems to no longer be necessary (either it was
never necessary or the underlying browser bug that made it necessary was
fixed).

Before: ![code links before][2]
After: ![code links after][3]

[1]: https://next.angular.io/guide/workspace-config#generation-schematics
[2]: https://user-images.githubusercontent.com/8604205/115149753-34589780-a06e-11eb-8d4e-825b5e94282d.png
[3]: https://user-images.githubusercontent.com/8604205/115149755-3589c480-a06e-11eb-9b15-825d75c74878.png

PR Close #41694

aio/src/styles/0-base/_typography.scss

@@ -210,7 +210,6 @@ code {
       > a {
         &[href^="http:"],
         &[href^="https:"] {
-          display: inline-flex;
           padding-right: calc(1em + 0.25rem);
           position: relative;
 

aio/src/styles/2-modules/_presskit.scss

@@ -50,7 +50,6 @@
           padding: 0;
 
           a {
-            display: inline-flex;
             padding-right: 3rem;
             position: relative;