Repository: brazilian-utils/brutils-python (python)

Issue:
Add formatCNPJ method
In order to make it with the same API as [js brutils](https://brazilian-utils.com.br/#/utilities?id=isvalidcnpj)

Pull request description:
adding format_cnpj method
closes #39 

Patch:
diff --git a/README.md b/README.md
index f64b346..a276ce4 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,8 @@ False
 ```
 >>> cpf.display('00011122233')
 '000.111.222-33'
->>> cnpj.display('00111222000100')
+>>> from brutils import format_cnpj
+>>> format_cnpj('00111222000100')
 '00.111.222/0001-00'
 ```
 
diff --git a/README_PT_BR.md b/README_PT_BR.md
index a3e2d18..107f607 100644
--- a/README_PT_BR.md
+++ b/README_PT_BR.md
@@ -56,7 +56,8 @@ False
 ```
 >>> cpf.display('00011122233')
 '000.111.222-33'
->>> cnpj.display('00111222000100')
+>>> from brutils import format_cnpj
+>>> format_cnpj('00111222000100')
 '00.111.222/0001-00'
 ```
 
diff --git a/brutils/__init__.py b/brutils/__init__.py
index 8fa0305..bace502 100644
--- a/brutils/__init__.py
+++ b/brutils/__init__.py
@@ -1,2 +1,2 @@
 from brutils.cpf import is_valid as is_valid_cpf
-from brutils.cnpj import is_valid as is_valid_cnpj
+from brutils.cnpj import is_valid as is_valid_cnpj, format_cnpj
diff --git a/brutils/cnpj.py b/brutils/cnpj.py
index 7e25db9..39bdcb8 100644
--- a/brutils/cnpj.py
+++ b/brutils/cnpj.py
@@ -28,6 +28,14 @@ def display(cnpj):  # type: (str) -> str
     )
 
 
+def format_cnpj(cnpj):  # type: (str) -> str
+    """
+    Will format an adequately formatted numbers-only CNPJ string,
+    adding in standard formatting visual aid symbols for display.
+    """
+    return display(cnpj)
+
+
 # CALCULATORS
 #############
 


Test patch:
diff --git a/tests/test_cnpj.py b/tests/test_cnpj.py
index ac7b757..78e18b9 100644
--- a/tests/test_cnpj.py
+++ b/tests/test_cnpj.py
@@ -16,6 +16,7 @@ from brutils.cnpj import (
     validate,
     generate,
     is_valid,
+    format_cnpj,
 )
 from unittest import TestCase, main
 
@@ -35,6 +36,12 @@ class CNPJ(TestCase):
         assert display("0000000000000a") is None
         assert display("0000000000000") is None
 
+    def test_format_cnpj(self):
+        assert format_cnpj("00000000000109") == "00.000.000/0001-09"
+        assert format_cnpj("00000000000000") is None
+        assert format_cnpj("0000000000000a") is None
+        assert format_cnpj("0000000000000") is None
+
     def test_hashdigit(self):
         assert hashdigit("00000000000000", 13) == 0
         assert hashdigit("00000000000000", 14) == 0