fix: Typos (#15401)

Author: cleptric

develop-docs/sdk/telemetry/spans/span-api.mdx

@@ -52,7 +52,7 @@ interface Span {
 When implementing the span interface, consider the following guidelines:
 
 - SDKs MAY implement additional APIs, such as getters/setters for properties (e.g. `span.getStatus()`), or additional methods for convenience (e.g. `Span::spanContext()`). 
-- SDK implementers SHOULD dissalow direct mutation (without setters) of span properties such as the span name, depending on the plaform and the challenges involved.
+- SDK implementers SHOULD disallow direct mutation (without setters) of span properties such as the span name, depending on the platform and the challenges involved.
 - SDK implementers MAY disallow direct read access to span properties, depending on the platform and the challenges involved.
 
 ## Span Starting APIs