Clarity updates in instrumentation docs

Author: codyde

docs/platforms/javascript/common/tracing/instrumentation/index.mdx

@@ -36,7 +36,7 @@ In places where you are not able to execute your code in a callback (for example
 
 ## Span Hierarchy in the Browser
 
-In browser environments, spans are by default collected in a flat hierarchy where every span is the direct child of the root span. You can opt into a more fine-grained hierarchy but there are trade-offs.
+In browser environments, spans are by default collected in a flat hierarchy where every span is the direct child of the root span (the initial operation that kicks off the entire trace.). You can opt into a more fine-grained hierarchy but there are trade-offs.
 
 The key reason for keeping a flat hierarchy is because in browsers it's impossible to reliably keep track of the active span across asynchronous boundaries. This means that if multiple asynchronous operations are started in parallel, it is not possible to determine which span is the parent of which child span. Imagine the following example:
 

docs/platforms/javascript/common/tracing/span-metrics/index.mdx

@@ -102,7 +102,6 @@ Sentry.init({
    - Use clear, consistent naming patterns
    - Include the metric category (examples: `db`, `cache`, `http`)
    - Use snake_case for metric names
-   - Avoid high-cardinality values in metric names
 
 2. **Data Types**
    - Use appropriate numeric types for measurements
@@ -111,14 +110,11 @@ Sentry.init({
    - Use arrays when grouping related values
 
 3. **Performance Considerations**
-   - Avoid adding too many metrics to a single span
    - Consider the overhead of metric collection
    - Use sampling when collecting high-frequency metrics
    - Balance metric granularity with system performance
 
 4. **Debugging and Monitoring**
-   - Include relevant error and status information
-   - Add timestamps for important events
    - Include correlation IDs for related operations
    - Add context that helps with troubleshooting