Adding docs for basic usage

Author: EkberHasanov

docs/pandas_types.md

@@ -0,0 +1,24 @@
+
+The `Series` class provides support for working with pandas Series objects.
+
+```py
+import pandas as pd
+from pydantic import BaseModel
+
+from pydantic_extra_types.pandas_types import Series
+
+
+class MyData(BaseModel):
+    numbers: Series[int]
+
+
+data = {"numbers": pd.Series([1, 2, 3, 4, 5])}
+my_data = MyData(**data)
+
+print(my_data.numbers)
+# > 0    1
+# > 1    2
+# > 2    3
+# > 3    4
+# > 4    5
+# > dtype: int64