Update README

Updates readme Quickstart section to include passing `calendars` and
`dealys` if Yahoo API not fully available.

README.md

@@ -26,6 +26,8 @@ $ pip install market-prices
 ```python
 >>> from market_prices import PricesYahoo
 >>> prices = PricesYahoo("MSFT")  # prices for a single instrument, Microsoft
+>>> # OR if Yahoo API endpoints are not all currently available in your region...
+>>> prices = PricesYahoo("MSFT", calendars="XNYS", delays=0)
 >>> prices.get("5min", minutes=40)  # last 40 minutes of prices at 5 minute intervals
 ```
 ```
@@ -100,6 +102,10 @@ Although some indices are longer than three calendar days, they all comprise of
 ```python
 >>> # Get a prices instance for Microsoft in New York, Alibaba in Hong Kong and 24/7 Bitcoin
 >>> prices_mult = PricesYahoo("MSFT, 9988.HK, BTC-USD")
+>>> # OR if Yahoo API endpoints are not all currently available in your region...
+>>> prices_mult = PricesYahoo(
+    "MSFT, 9988.HK, BTC-USD", calendars=["XNYS", "XHKG", "24/7"], delays=[0, 15, 0]
+)
 >>> # lead_symbol determines the exchange against which the period will be evaluated and
 >>> # the default output time zone (which for Bitcoin is UTC).
 >>> prices_mult.get("90T", hours=9, lead_symbol="BTC-USD")

tests/test_yahoo.py

@@ -991,7 +991,7 @@ def prices(
         api_working = True
         try:
             prices = m.PricesYahoo(symbols)
-        except m.YahooAPIError:
+        except (m.YahooAPIError, ValueError):
             prices = m.PricesYahoo(symbols, calendars=calendars, delays=delays)
             api_working = False
         yield prices, api_working