fix(docs): Update pnpm install commands (#516)

Co-authored-by: Luca Forstner <luca.forstner@sentry.io>

Author: et84121

packages/babel-plugin-component-annotate/README.md

@@ -46,7 +46,7 @@ yarn add @sentry/babel-plugin-component-annotate --dev
 Using pnpm:
 
 ```bash
-pnpm install @sentry/babel-plugin-component-annotate --dev
+pnpm add @sentry/babel-plugin-component-annotate --save-dev
 ```
 
 ## Example

packages/esbuild-plugin/README_TEMPLATE.md

@@ -29,7 +29,7 @@ yarn add @sentry/esbuild-plugin --dev
 Using pnpm:
 
 ```bash
-pnpm install @sentry/esbuild-plugin --dev
+pnpm add @sentry/esbuild-plugin --save-dev
 ```
 
 ## Example

packages/rollup-plugin/README_TEMPLATE.md

@@ -29,7 +29,7 @@ yarn add @sentry/rollup-plugin --dev
 Using pnpm:
 
 ```bash
-pnpm install @sentry/rollup-plugin --dev
+pnpm add @sentry/rollup-plugin --save-dev
 ```
 
 ## Example

packages/vite-plugin/README_TEMPLATE.md

@@ -29,7 +29,7 @@ yarn add @sentry/vite-plugin --dev
 Using pnpm:
 
 ```bash
-pnpm add -D @sentry/vite-plugin
+pnpm add @sentry/vite-plugin --save-dev
 ```
 
 ## Example

packages/webpack-plugin/README_TEMPLATE.md

@@ -29,7 +29,7 @@ yarn add @sentry/webpack-plugin --dev
 Using pnpm:
 
 ```bash
-pnpm install @sentry/webpack-plugin --dev
+pnpm add @sentry/webpack-plugin --save-dev
 ```
 
 ## Example