fix link to let's encrypt doc (#8294)

docs/tls/README.md

@@ -13,7 +13,7 @@ Install MinIO Server using the instructions in the [MinIO Quickstart Guide](http
 
 ## <a name="use-an-existing-key-and-certificate-with-minio"></a>2. Use an Existing Key and Certificate with MinIO 
 
-This section describes how to use a private key and public certificate that have been obtained from a certificate authority (CA). If these files have not been obtained, skip to [3. Generate Self-signed Certificates](#generate-use-self-signed-keys-certificates) or generate them with [Let's Encrypt](https://letsencrypt.org) using these instructions: [https://docs.min.io/docs/generate-let-s-encypt-certificate-using-concert-for-minio](https://docs.min.io/docs/).
+This section describes how to use a private key and public certificate that have been obtained from a certificate authority (CA). If these files have not been obtained, skip to [3. Generate Self-signed Certificates](#generate-use-self-signed-keys-certificates) or generate them with [Let's Encrypt](https://letsencrypt.org) using these instructions: [Generate let's encypt certificate using concert for minio](https://docs.min.io/docs/generate-let-s-encypt-certificate-using-concert-for-minio.html).
 
 Copy the existing private key and public certificate to the `certs` directory. The default certs directory is:
 * **Linux:** `${HOME}/.minio/certs`