Update CPI docstring (#5856)

* docstring

* pep8

* caps

* rip

---------

Co-authored-by: Danglewood <85772166+deeleeramone@users.noreply.github.com>

openbb_platform/core/openbb_core/provider/standard_models/cpi.py

@@ -80,9 +80,11 @@ class ConsumerPriceIndexQueryParams(QueryParams):
         description=QUERY_DESCRIPTIONS.get("units", "")
         + """
     Options:
-    - `growth_previous`: growth from the previous period
-    - `growth_same`: growth from the same period in the previous year
-    - `index_2015`: index with base year 2015.""",
+    - `growth_previous`: Percent growth from the previous period.
+      If monthly data, this is month-over-month, etc
+    - `growth_same`: Percent growth from the same period in the previous year.
+      If looking at monthly data, this would be year-over-year, etc.
+    - `index_2015`: Rescaled index value, such that the value in 2015 is 100.""",
     )
     frequency: CPI_FREQUENCY = Field(
         default="monthly",

openbb_platform/extensions/economy/openbb_economy/economy_router.py

@@ -36,7 +36,7 @@ async def cpi(
     standard_params: StandardParams,
     extra_params: ExtraParams,
 ) -> OBBject[BaseModel]:
-    """Consumer Price Index (CPI) Data."""
+    """Consumer Price Index (CPI).  Returns either the rescaled index value, or a rate of change (inflation)."""
     return await OBBject.from_query(Query(**locals()))