docs: document that price field may be absent in Lazer payload reference (#905)

* docs: add documentation for null price values in Lazer payload reference

- Added example JSON showing price field with null value
- Added info callout explaining null price behavior
- Added warning callout in Aggregate Market Price section
- Documented that null indicates price could not be computed
- Advised users to use last valid price or wait for fresh update

Co-Authored-By: Nidhi Singh <[email protected]>

* fix: apply prettier formatting

Co-Authored-By: Nidhi Singh <[email protected]>

* docs: update to show missing price fields as absent instead of null

- Changed JSON example to show fields as absent rather than null
- Updated callouts to reflect that fields are missing/absent
- Clarified that price fields may be omitted from response when not computable

Co-Authored-By: Nidhi Singh <[email protected]>

* docs: simplify documentation - remove example and focus on price field only

- Removed third price feed example from JSON
- Removed info callout that explained the example
- Simplified warning callout to only mention price field
- Removed mention of related optional fields (bestBidPrice, bestAskPrice, confidence)

Co-Authored-By: Nidhi Singh <[email protected]>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Nidhi Singh <[email protected]>

Author: devin-ai-integration[bot]

pages/lazer/payload-reference.mdx

@@ -115,6 +115,13 @@ Main aggregate price calculated from all contributing publishers
 - **Algorithm**: Refer to [price aggregation](../../price-feeds/how-pyth-works/price-aggregation) for the current algorithm
 - **Invariants**: Non-zero when present (null values filtered out)
 
+<Callout type="warning">
+  **Missing Price Field**: In some cases, the `price` field may be absent from
+  the response. This indicates that the price could not be computed at that
+  moment. When this occurs, you should either use the last valid price you
+  received or wait for a fresh update with a valid price.
+</Callout>
+
 #### Data Publisher Count - `publisher_count`
 
 Number of data publishers contributing to this price feed