DOCSP-42382: Update connection string placeholders (#56)

* DOCSP-42382: Update connection string placeholders

* edits

Author: norareidy

source/connect/client.txt

@@ -54,7 +54,7 @@ A standard connection string includes the following components:
      - Required. A prefix that identifies this as a string in the
        standard connection format.
 
-   * - ``username:password``
+   * - ``db_username:db_password``
 
      - Optional. Authentication credentials. If you include these, the client
        authenticates the user against the database specified in ``authSource``.
@@ -69,7 +69,7 @@ A standard connection string includes the following components:
    * - ``/defaultauthdb``
 
      - Optional. The authentication database to use if the
-       connection string includes ``username:password@``
+       connection string includes ``db_username:db_password@``
        authentication credentials but not the ``authSource`` option. If you don't include 
        this component, the client authenticates the user against the ``admin`` database.
 

source/includes/authentication.cpp

@@ -1,11 +1,11 @@
 // start-scram-sha-256
-auto uri = mongocxx::uri("mongodb://<username>:<password>@<hostname>:<port>/?"
+auto uri = mongocxx::uri("mongodb://<db_username>:<db_password>@<hostname>:<port>/?"
                          "authSource=admin&authMechanism=SCRAM-SHA-256");
 auto client = mongocxx::client(uri);
 // end-scram-sha-256
 
 // start-scram-sha-1
-auto uri = mongocxx::uri("mongodb://<username>:<password>@<hostname>:<port>/?"
+auto uri = mongocxx::uri("mongodb://<db_username>:<db_password>@<hostname>:<port>/?"
                          "authSource=admin&authMechanism=SCRAM-SHA-1");
 auto client = mongocxx::client(uri);
 // end-scram-sha-1
@@ -35,14 +35,14 @@ auto client = mongocxx::client(uri);
 // end-aws-environment
 
 // start-kerberos
-auto uri = mongocxx::uri("mongodb://mongodbuser%40EXAMPLE.COM@<hostname>:<port>/?"
+auto uri = mongocxx::uri("mongodb://<Kerberos principal>@<hostname>:<port>/?"
                          "authMechanism=GSSAPI"
                          "&authMechanismProperties=SERVICE_NAME:<authentication service name>");
 auto client = mongocxx::client(uri);
 // end-kerberos
 
 // start-plain
-auto uri = mongocxx::uri("mongodb://<username>:<password>@<hostname>:<port>/?"
+auto uri = mongocxx::uri("mongodb://<db_username>:<db_password>@<hostname>:<port>/?"
                          "authMechanism=PLAIN&tls=true");
 auto client = mongocxx::client(uri);
 // end-plain

source/security/authentication.txt

@@ -34,8 +34,8 @@ running MongoDB v4.0 or later.
 
 To authenticate with this mechanism, set the following connection options:
 
-- ``username``: The username to authenticate.
-- ``password``: The password to authenticate.
+- ``db_username``: The database username to authenticate.
+- ``db_password``: The database password to authenticate.
 - ``authSource``: The MongoDB database to authenticate against. By default,
   {+driver-short+} authenticates against the database in the connection
   URI, if you include one. If you don't, it authenticates against the ``admin`` database.
@@ -61,8 +61,8 @@ running MongoDB v3.6.
 
 To authenticate with this mechanism, set the following connection options:
 
-- ``username``: The username to authenticate. 
-- ``password``: The password to authenticate.
+- ``db_username``: The username to authenticate. 
+- ``db_password``: The password to authenticate.
 - ``authSource``: The MongoDB database to authenticate against. By default,
   {+driver-short+} authenticates against the ``admin`` database.
 - ``authMechanism``: Set to ``"SCRAM-SHA-1"``.

source/security/enterprise-authentication.txt

@@ -72,7 +72,7 @@ Complete the following steps to authenticate with GSSAPI:
 
       Next, set the following connection options:
 
-      - ``username``: The Kerbos principal to authenticate.
+      - ``Kerberos principal``: The Kerberos principal to authenticate.
       - ``authMechanism``: Set to ``"GSSAPI"``.
       - ``authMechanismProperties``: Optional. By default, MongoDB uses ``mongodb`` as
         the authentication service name. To specify a different service name, set