Update README.md

Author: tilman

README.md

@@ -31,17 +31,17 @@ Tested versions are:
 ## Available Options (needs Option B of getting started)
 
 | Option                 | Description                                                                                                       | Default Value                                         |
-| ---------------------- | ----------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------- | --- | ----------------- |
+| ---------------------- | ----------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------- |
 | database               | Redis database number to use. Uses DB 0 for production, DB 1 otherwise                                            | `process.env.VERCEL_ENV === 'production' ? 0 : 1`     |
-| keyPrefix              | Prefix added to all Redis keys                                                                                    | `process.env.VERCEL_URL                               |     | 'UNDEFINED*URL*'` |
+| keyPrefix              | Prefix added to all Redis keys                                                                                    | `process.env.VERCEL_URL    \|\| 'UNDEFINED_URL_'`     |
 | sharedTagsKey          | Key used to store shared tags hash map in Redis                                                                   | `'__sharedTags__'`                                    |
 | timeoutMs              | Timeout in milliseconds for Redis operations                                                                      | `5000`                                                |
 | revalidateTagQuerySize | Number of entries to query in one batch during full sync of shared tags hash map                                  | `250`                                                 |
 | avgResyncIntervalMs    | Average interval in milliseconds between tag map full re-syncs                                                    | `3600000` (1 hour)                                    |
 | redisGetDeduplication  | Enable deduplication of Redis get requests via internal in-memory cache.                                          | `true`                                                |
 | inMemoryCachingTime    | Time in milliseconds to cache Redis get results in memory. Set this to 0 to disable in-memory caching completely. | `10000`                                               |
 | defaultStaleAge        | Default stale age in seconds for cached items                                                                     | `1209600` (14 days)                                   |
-| estimateExpireAge      | Function to calculate expire age (redis TTL value) from stale age                                                 | Production: `staleAge * 2`<br>Other: `staleAge * 1.2` |
+| estimateExpireAge      | Function to calculate expire age (redis TTL value) from stale age                                                 | Production: `staleAge * 2`<br> Other: `staleAge * 1.2`|
 
 ## Getting started