doc(docstring): fix docstring example of LicenseContextManager (#2679)

Author: PProfizi

src/ansys/dpf/core/server_context.py

@@ -118,6 +118,7 @@ class LicenseContextManager:
     Examples
     --------
     Using a context manager
+
     >>> from ansys.dpf import core as dpf
     >>> dpf.set_default_server_context(dpf.AvailableServerContexts.premium)
     >>> field = dpf.Field()
@@ -129,13 +130,15 @@ class LicenseContextManager:
     ...    out = op.outputs.field()
 
     Using an instance
+
     >>> lic = dpf.LicenseContextManager()
     >>> op.inputs.field(field)
     >>> op.inputs.threshold(0.0)
     >>> out = op.outputs.field()
     >>> lic = None
 
     Using a context manager and choosing license options
+
     >>> op.inputs.field(field)
     >>> op.inputs.threshold(0.0)
     >>> out = op.outputs.field()
@@ -149,6 +152,7 @@ class LicenseContextManager:
     Notes
     -----
     Available from 6.1 server version.
+
     """
 
     def __init__(