[KeyVault] Documenting the lack of browser support (Azure#9716)

* [KeyVault] Documenting the lack of browser support

Here's what comes to mind. Feedback appreciated.

Once approved:
Fixes Azure#9033

* typo

* feedback, and same note in other READMEs

* colon

* feedback by Ramya

Author: sadasant

sdk/keyvault/keyvault-certificates/README.md

@@ -16,6 +16,8 @@ Use the client library for Azure Key Vault Certificates in your Node.js applicat
 - Get all certificates.
 - Get all deleted certificates.
 
+> Note: This package cannot be used in the browser due to Azure Key Vault service limitations.
+
 [Source code](https://github.com/Azure/azure-sdk-for-js/tree/master/sdk/keyvault/keyvault-certificates) | [Package (npm)](https://www.npmjs.com/package/@azure/keyvault-certificates) | [API Reference Documentation](https://docs.microsoft.com/javascript/api/@azure/keyvault-certificates) | [Product documentation](https://azure.microsoft.com/en-us/services/key-vault/) | [Samples](./samples)
 
 ## Getting started

sdk/keyvault/keyvault-keys/README.md

@@ -6,15 +6,15 @@ If you would like to know more about Azure Key Vault, you may want to review: [W
 Azure Key Vault Key management allows you to create and control 
 encryption keys that encrypt your data.
 
-Use the client library for Azure Key Vault Keys in your Node.js application to
+Use the client library for Azure Key Vault Keys in your Node.js application to:
 
 - Create keys using elliptic curve or RSA encryption, optionally backed by Hardware Security Modules (HSM).
 - Import, Delete, and Update keys.
 - Get one or more keys and deleted keys, with their attributes.
 - Recover a deleted key and restore a backed up key.
 - Get the versions of a key.
 
-Using the cryptography client available in this library you also have access to
+Using the cryptography client available in this library you also have access to:
 
 - Encrypting
 - Decrypting
@@ -23,6 +23,8 @@ Using the cryptography client available in this library you also have access to
 - Wrapping keys
 - Unwrapping keys
 
+> Note: This package cannot be used in the browser due to Azure Key Vault service limitations.
+
 [Source code](https://github.com/Azure/azure-sdk-for-js/tree/master/sdk/keyvault/keyvault-keys) | [Package (npm)](https://www.npmjs.com/package/@azure/keyvault-keys) | [API Reference Documentation](https://docs.microsoft.com/javascript/api/@azure/keyvault-keys) | [Product documentation](https://azure.microsoft.com/en-us/services/key-vault/) | [Samples](./samples)
 
 ## Getting started

sdk/keyvault/keyvault-secrets/README.md

@@ -7,7 +7,7 @@ Azure Key Vault Secrets management allows you to securely store and
 tightly control access to tokens, passwords, certificates, API keys,
 and other secrets.
 
-Use the client library for Azure Key Vault Secrets in your Node.js application to
+Use the client library for Azure Key Vault Secrets in your Node.js application to:
 
 - Get, set and delete secrets.
 - Update a secret and it's attributes.
@@ -17,6 +17,8 @@ Use the client library for Azure Key Vault Secrets in your Node.js application t
 - Get all secrets.
 - Get all deleted secrets.
 
+> Note: This package cannot be used in the browser due to Azure Key Vault service limitations.
+
 [Source code](https://github.com/Azure/azure-sdk-for-js/tree/master/sdk/keyvault/keyvault-secrets) | [Package (npm)](https://www.npmjs.com/package/@azure/keyvault-secrets) | [API Reference Documentation](https://docs.microsoft.com/javascript/api/@azure/keyvault-secrets) | [Product documentation](https://azure.microsoft.com/en-us/services/key-vault/) | [Samples](./samples)
 
 ## Getting started