Fix text sizing of feature gate table (#527)

## Description

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Fixes text sizing
## Type of change

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-   [ ] Bug fix
-   [ ] New feature
-   [ ] Protocol integration
-   [ ] Documentation update
-   [x] Other (please describe): readability

## Screenshots

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showing the changes -->
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## Testing

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## Related Issues

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## Checklist

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review -->

-   [x] My code follows the project's style guidelines
-   [ ] I have added tests that prove my fix/feature works
-   [x] All tests pass locally and in CI 
-   [ ] I have updated documentation as needed
-   [ ] CI/CD checks pass
-   [ ] I have included screenshots for protocol screens (if applicable)
- [ ] For security-related features, I have included links to related
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## Additional Notes

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<!-- ELLIPSIS_HIDDEN -->

----

> [!IMPORTANT]
> Adjusts text sizes in feature gate table for improved readability by
modifying SCSS and TSX files.
> 
>   - **CSS Adjustments**:
> - Added `.small-headers` class in `_tables.scss` to set `font-size` to
`0.7125rem` for table headers.
> - Applied `.small-headers` class to `div` in `featureGate.tsx` to
adjust header text size.
>   - **HTML Structure**:
> - Changed `<h3>` to `<h4>` in `featureGate.tsx` for card header title.
> - Added `fs-sm` class to various elements in `featureGate.tsx` to
standardize small font size for feature titles, descriptions, and
buttons.
> 
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=solana-foundation%2Fexplorer&utm_source=github&utm_medium=referral)<sup>
for cd93dfc. It will automatically
update as commits are pushed.</sup>

<!-- ELLIPSIS_HIDDEN -->

Author: ngundotra

app/scss/dashkit/_tables.scss

@@ -28,6 +28,10 @@ tbody td {
     border-bottom: 0;
 }
 
+.small-headers thead th {
+    font-size: 0.7125rem !important;
+}
+
 .table-sep {
     background-color: $table-head-bg;
     text-transform: uppercase;

app/utils/feature-gate/featureGate.tsx

@@ -61,12 +61,12 @@ export function UpcomingFeatures() {
     return (
         <div className="card">
             <div className="card-header">
-                <h3 className="card-header-title">
+                <h4 className="card-header-title">
                     <span className="me-2">🚀</span>
                     Upcoming {clusterName(cluster)} Features
-                </h3>
+                </h4>
             </div>
-            <div className="table-responsive">
+            <div className="table-responsive small-headers">
                 <table className="table">
                     <thead>
                         <tr>
@@ -81,7 +81,7 @@ export function UpcomingFeatures() {
                             <tr key={feature.key}>
                                 <td>
                                     <div className="mb-2 d-flex align-items-center">
-                                        <p className="mb-0 me-3 text-decoration-underline">{feature.title}</p>
+                                        <p className="mb-0 me-3 text-decoration-underline fs-sm">{feature.title}</p>
                                         {cluster === Cluster.MainnetBeta && feature.mainnetActivationEpoch && (
                                             <span className="badge bg-success">Active on Mainnet</span>
                                         )}
@@ -92,10 +92,10 @@ export function UpcomingFeatures() {
                                             <span className="badge bg-success">Active on Testnet</span>
                                         )}
                                     </div>
-                                    <p className="mb-0">{feature.description}</p>
+                                    <p className="mb-0 fs-sm">{feature.description}</p>
                                 </td>
                                 <td>
-                                    <div className="d-flex flex-column">
+                                    <div className="d-flex flex-column fs-sm">
                                         {feature.mainnetActivationEpoch && (
                                             <Link
                                                 href={`/epoch/${feature.mainnetActivationEpoch}?cluster=mainnet`}
@@ -135,7 +135,7 @@ export function UpcomingFeatures() {
                                             href={feature.simd_link}
                                             target="_blank"
                                             rel="noopener noreferrer"
-                                            className="btn btn-sm btn-outline-primary"
+                                            className="btn btn-sm btn-outline-primary fs-sm"
                                         >
                                             SIMD {feature.simd}
                                         </a>