chore: Improve Vercel/Neon syncEnvVars build extensions docs (#2747)

chore: Improve Vercel/Neon `syncEnvVars` build extensions docs

Author: 0ski

docs/config/extensions/syncEnvVars.mdx

@@ -126,7 +126,7 @@ export default defineConfig({
     extensions: [
       syncVercelEnvVars({
         projectId: "your-vercel-project-id",
-        vercelAccessToken: "your-vercel-access-token",
+        vercelAccessToken: "your-vercel-access-token", // optional, we recommend to keep it as env variable
         vercelTeamId: "your-vercel-team-id", // optional
       }),
     ],
@@ -190,7 +190,7 @@ export default defineConfig({
     extensions: [
       syncNeonEnvVars({
         projectId: "your-neon-project-id",
-        neonAccessToken: "your-neon-access-token",
+        neonAccessToken: "your-neon-access-token", // optional, we recommend to keep it as env variable
         branch: "your-branch-name", // optional, defaults to ctx.branch
         databaseName: "your-database-name", // optional, defaults to the first database
         roleName: "your-role-name", // optional, defaults to the database owner

packages/build/src/extensions/core/neonSyncEnvVars.ts

@@ -74,6 +74,10 @@ function buildNeonEnvVarMappings(options: {
 
 export function syncNeonEnvVars(options?: {
   projectId?: string;
+  /**
+   * Neon API access token for authentication.
+   * It's recommended to use the NEON_ACCESS_TOKEN environment variable instead of hardcoding this value.
+   */
   neonAccessToken?: string;
   branch?: string;
   databaseName?: string;

packages/build/src/extensions/core/vercelSyncEnvVars.ts

@@ -13,6 +13,10 @@ type VercelEnvVar = {
 
 export function syncVercelEnvVars(options?: {
   projectId?: string;
+  /**
+   * Vercel API access token for authentication.
+   * It's recommended to use the VERCEL_ACCESS_TOKEN environment variable instead of hardcoding this value.
+   */
   vercelAccessToken?: string;
   vercelTeamId?: string;
   branch?: string;