Remove secrets.template.env

This file is no longer needed as we are using GitHub secrets for the environment variables.

.gitignore

@@ -1,2 +1 @@
-secrets.env
 youtube-video-list

.markdownlint.json

@@ -0,0 +1,3 @@
+{
+    "MD013": true
+}

.vscode/launch.json

@@ -14,7 +14,6 @@
         "-after",
         "2019-12-26T00:00:00Z",
       ],
-      "envFile": "${workspaceFolder}/secrets.env",
     }
   ]
 }

README.md

@@ -18,14 +18,13 @@ To run this program, you will need the following:
   this time, it appears re:Invent 2019 videos were posted between December 3 and
   December 26.
 
-Before running, you need to copy `secrets.template.env` to `secrets.env` and
-replace the placeholder with your YouTube Data API Key.
+Before running, you need to the environment variable `YOUTUBE_APIKEY` to your
+YouTube Data API Key.
 
 Then you can build and run the program:
 
-```
+```sh
 make
-set -o allexport; source secrets.env; set +o allexport
 ./youtube-video-list \
   -channel UCdoadna9HFHsxXWhafhNvKw \
   -after 2019-12-01T00:00:00Z \
@@ -38,16 +37,14 @@ take a minute or two to return.
 
 I wrote a Python version of this program. You can run:
 
-```
+```sh
 pip install -r requirements.txt
-set -o allexport; source secrets.env; set +o allexport
 python youtube-video-list.py \
   --channel UCdoadna9HFHsxXWhafhNvKw \
   --after 2019-12-01T00:00:00Z \
   --before 2019-12-28T00:00:00Z
 ```
 
-
 [YouTube Data API Overview]: https://developers.google.com/youtube/v3/getting-started
 [AWS Events]: https://www.youtube.com/channel/UCdoadna9HFHsxXWhafhNvKw/videos
 [Understanding your channel URLs]: https://support.google.com/youtube/answer/6180214?hl=en