Replace more single quotes

doc/source/datasets.md

@@ -34,27 +34,27 @@ The code below shows how to read all records in the [MESA](https://sleepdata.org
 ```python
 from sleepecg import read_mesa, set_nsrr_token
 
-set_nsrr_token('<your-download-token-here>')
+set_nsrr_token("<your-download-token-here>")
 mesa = read_mesa()  # note that this is a generator
 ```
 
 You can also select a subset of records from a dataset. This example will download and read all records having IDs starting with `00` (i.e. records `0001`-`0099`):
 ```python
 from sleepecg import read_mesa, set_nsrr_token
 
-set_nsrr_token('<your-download-token-here>')
-mesa = read_mesa(records_pattern='00*')  # note that this is a generator
+set_nsrr_token("<your-download-token-here>")
+mesa = read_mesa(records_pattern="00*")  # note that this is a generator
 ```
 
 If you just want to download NSRR data (like with the [NSRR Ruby Gem](https://github.com/nsrr/nsrr-gem)), use the workflow below. The example downloads all files within [`mesa/polysomnography/edfs`](https://sleepdata.org/datasets/mesa/files/polysomnography/edfs) matching `*-00*` to a local folder `./datasets` (subfolders are created to preserve the dataset's directory structure).
 ```python
 from sleepecg import download_nsrr, set_nsrr_token
 
-set_nsrr_token('<your-download-token-here>')
+set_nsrr_token("<your-download-token-here>")
 download_nsrr(
-    db_slug='mesa',
-    subfolder='polysomnography/edfs',
-    pattern='*-00*',
-    data_dir='./datasets',
+    db_slug="mesa",
+    subfolder="polysomnography/edfs",
+    pattern="*-00*",
+    data_dir="./datasets",
 )
 ```