docs(install): Clarify & Match tsconfig Edits (shadcn-ui#1642)

This is a small update to the installation instructions for some of the frameworks to make the instructions on editing the tsconfig file consistant across the frameworks, and remove some potentially confusing wording (if people read too fast...like me). 

Mainly applying the gatsby tsconfig instructions to vite and astro, as it is the most clear. 
Additionally changed the wording from:
```
 Add the code below to the compilerOptions...
```
to:
```
Add the following code to the compilerOptions...
```
to avoid people easily misreading it as "add the code **below the** compilerOptions".

content/docs/installation/astro.mdx

@@ -62,15 +62,19 @@ Answer `Yes` to all the question prompted by the CLI when installing Tailwind CS
 
 ### Edit tsconfig.json file
 
-Add the code below to the tsconfig.json file to resolve paths:
+Add the following code to the `tsconfig.json` file to resolve paths:
 
-```json {2-7} showLineNumbers
+```ts {4-9} showLineNumbers
 {
   "compilerOptions": {
+    // ...
     "baseUrl": ".",
     "paths": {
-      "@/*": ["src/*"]
+      "@/*": [
+        "./src/*"
+      ]
     }
+    // ...
   }
 }
 ```

content/docs/installation/gatsby.mdx

@@ -35,7 +35,7 @@ You will be asked a few questions to configure your project:
 
 ### Edit tsconfig.json file
 
-Add the code below to the `tsconfig.json` file to resolve paths:
+Add the following code to the `tsconfig.json` file to resolve paths:
 
 ```ts {4-9} showLineNumbers
 {

content/docs/installation/vite.mdx

@@ -23,20 +23,28 @@ npm install -D tailwindcss postcss autoprefixer
 npx tailwindcss init -p
 ```
 
-### Edit tsconfig.json
-
-Add the code below to the compilerOptions of your tsconfig.json so your app can resolve paths without error
-
-```typescript
-"baseUrl": ".",
-"paths": {
-  "@/*": ["./src/*"]
+### Edit tsconfig.json file
+
+Add the following code to the `tsconfig.json` file to resolve paths:
+
+```ts {4-9} showLineNumbers
+{
+  "compilerOptions": {
+    // ...
+    "baseUrl": ".",
+    "paths": {
+      "@/*": [
+        "./src/*"
+      ]
+    }
+    // ...
+  }
 }
 ```
 
 ### Update vite.config.ts
 
-Add the code below to the vite.config.ts so your app can resolve paths without error
+Add the following code to the vite.config.ts so your app can resolve paths without error
 
 ```bash
 # (so you can import "path" without error)