chore(a11y): improving a11y score to 100% for home and doc pages (#1406)

* chore(a11y): improving a11y score to 100% for home and doc pages

* chore(a11y): addressing comments

Author: StephNathai

src/css/custom.css

@@ -2,8 +2,16 @@
   --ifm-light-background-color: var(--ifm-color-emphasis-100);
 }
 
-html[data-theme='dark'] {
-  --ifm-link-color: #679df5;
+[data-theme='dark']:root {
+  --ifm-color-primary: #7FA8F1;
+  --ifm-link-color: #7FA8F1;
+  --docsearch-muted-color: white;
+}
+
+[data-theme='light']:root {
+  --ifm-color-primary: #1554B7;
+  --ifm-link-color: #1554B7;
+  --docsearch-muted-color: #494B5F;
 }
 
 .wrapper {
@@ -75,6 +83,10 @@ html[data-theme='dark'] {
   line-height: 1em;
 }
 
+.theme-doc-markdown {
+  --ifm-link-decoration: underline;
+}
+
 @media only screen and (min-width: 480px) {
   .projectTitle {
     font-size: 300%;