rename placeholders for consistency with UI

Author: ayoisaiah

examples/logger/README.md

@@ -13,12 +13,12 @@ yarn install
 Then, run the development server with `LOGTAIL_SOURCE_TOKEN` and `LOGTAIL_URL` environment variable:
 
 ```bash
-LOGTAIL_SOURCE_TOKEN=<source-token> LOGTAIL_URL=<ingesting-host> npm run dev
+LOGTAIL_SOURCE_TOKEN=<source_token> LOGTAIL_URL=<ingestion_host> npm run dev
 # or
-LOGTAIL_SOURCE_TOKEN=<source-token> LOGTAIL_URL=<ingesting-host> yarn dev
+LOGTAIL_SOURCE_TOKEN=<source_token> LOGTAIL_URL=<ingestion_host> yarn dev
 ```
 
-_Don't forget to replace `<source-token>` and `<ingesting-host>` with your actual source token and ingesting host which you can find by going to **[Sources](https://telemetry.betterstack.com/team/0/sources) -> Configure** in Better Stack._
+_Don't forget to replace `<source_token>` and `<ingestion_host>` with your actual source token and ingesting host which you can find by going to **[Sources](https://telemetry.betterstack.com/team/0/sources) -> Configure** in Better Stack._
 
 Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
 
@@ -33,9 +33,9 @@ These endpoints can be edited in `pages/api/`.
 If you are using port 3000 for some other application, you can use a different port by running e.g.:
 
 ```bash
-LOGTAIL_SOURCE_TOKEN=<source-token> LOGTAIL_URL=<ingesting-host> PORT=3001 npm run dev
+LOGTAIL_SOURCE_TOKEN=<source_token> LOGTAIL_URL=<ingestion_host> PORT=3001 npm run dev
 # or
-LOGTAIL_SOURCE_TOKEN=<source-token> LOGTAIL_URL=<ingesting-host> PORT=3001 yarn dev
+LOGTAIL_SOURCE_TOKEN=<source_token> LOGTAIL_URL=<ingestion_host> PORT=3001 yarn dev
 ```
 
 ## Learn More