docs: add API added in (elastic#984)

Author: bmorelli25

docs/api.asciidoc

@@ -17,6 +17,8 @@ as well as to mark the beginning and end of transactions.
 [[client-api-init]]
 ==== Instantiation
 
+[small]#Added in v1.0.0.#
+
 To create a `Client` instance, import it and call its constructor:
 
 [source,python]
@@ -40,6 +42,8 @@ instantiate the client automatically.
 [[client-api-capture-exception]]
 ===== `Client.capture_exception()`
 
+[small]#Added in v1.0.0. `handled` added in v2.0.0.#
+
 Captures an exception object:
 
 [source,python]
@@ -63,6 +67,8 @@ Returns the id of the error as a string.
 [[client-api-capture-message]]
 ===== `Client.capture_message()`
 
+[small]#Added in v1.0.0.#
+
 Captures a message with optional added contextual data. Example:
 
 [source,python]
@@ -105,6 +111,9 @@ NOTE: Either the `message` or the `param_message` argument is required.
 [float]
 [[client-api-begin-transaction]]
 ===== `Client.begin_transaction()`
+
+[small]#Added in v1.0.0. `trace_parent` support added in v5.6.0.#
+
 Begin tracking a transaction.
 Should be called e.g. at the beginning of a request or when starting a background task. Example:
 
@@ -119,6 +128,9 @@ client.begin_transaction('processors')
 [float]
 [[client-api-end-transaction]]
 ===== `Client.end_transaction()`
+
+[small]#Added in v1.0.0.#
+
 End tracking the transaction.
 Should be called e.g. at the end of a request or when ending a background task. Example:
 
@@ -147,6 +159,8 @@ distributed tracing.
 [[api-traceparent-from-string]]
 ===== `elasticapm.trace_parent_from_string()`
 
+[small]#Added in v5.6.0.#
+
 Create a TraceParent object from the string representation generated by
 `TraceParent.to_string()`:
 
@@ -163,6 +177,8 @@ client.begin_transaction('processors', trace_parent=parent)
 [[api-traceparent-from-headers]]
 ===== `elasticapm.trace_parent_from_headers()`
 
+[small]#Added in v5.6.0.#
+
 Create a TraceParent object from HTTP headers (usually generated by another
 Elastic APM agent):
 
@@ -178,6 +194,8 @@ client.begin_transaction('processors', trace_parent=parent)
 [[api-traceparent-get-header]]
 ===== `elasticapm.get_trace_parent_header()`
 
+[small]#Added in v5.10.0.#
+
 Return the string representation of the current transaction TraceParent object:
 
 [source,python]
@@ -193,6 +211,8 @@ elasticapm.get_trace_parent_header()
 [[api-elasticapm-instrument]]
 ==== `elasticapm.instrument()`
 
+[small]#Added in v1.0.0.#
+
 Instruments libraries automatically.
 This includes a wide range of standard library and 3rd party modules.
 A list of instrumented modules can be found in `elasticapm.instrumentation.register`.
@@ -210,6 +230,8 @@ elasticapm.instrument()
 [[api-set-transaction-name]]
 ==== `elasticapm.set_transaction_name()`
 
+[small]#Added in v1.0.0.#
+
 Set the name of the current transaction.
 For supported frameworks, the transaction name is determined automatically,
 and can be overridden using this function. Example:
@@ -229,6 +251,8 @@ elasticapm.set_transaction_name('myapp.billing_process')
 [[api-set-transaction-result]]
 ==== `elasticapm.set_transaction_result()`
 
+[small]#Added in v2.2.0.#
+
 Set the result of the current transaction.
 For supported frameworks, the transaction result is determined automatically,
 and can be overridden using this function. Example:
@@ -248,6 +272,8 @@ elasticapm.set_transaction_result('SUCCESS')
 [[api-set-transaction-outcome]]
 ==== `elasticapm.set_transaction_outcome()`
 
+[small]#Added in v5.9.0.#
+
 Sets the outcome of the transaction. The value can either be `"success"`, `"failure"` or `"unknown"`.
 This should only be called at the end of a transaction after the outcome is determined.
 
@@ -298,6 +324,8 @@ elasticapm.set_transaction_outcome(OUTCOME.UNKNOWN)
 [[api-get-transaction-id]]
 ==== `elasticapm.get_transaction_id()`
 
+[small]#Added in v5.2.0.#
+
 Get the id of the current transaction. Example:
 
 [source,python]
@@ -312,6 +340,8 @@ transaction_id = elasticapm.get_transaction_id()
 [[api-get-trace-id]]
 ==== `elasticapm.get_trace_id()`
 
+[small]#Added in v5.2.0.#
+
 Get the `trace_id` of the current transaction's trace. Example:
 
 [source,python]
@@ -326,6 +356,8 @@ trace_id = elasticapm.get_trace_id()
 [[api-get-span-id]]
 ==== `elasticapm.get_span_id()`
 
+[small]#Added in v5.2.0.#
+
 Get the id of the current span. Example:
 
 [source,python]
@@ -340,6 +372,8 @@ span_id = elasticapm.get_span_id()
 [[api-set-custom-context]]
 ==== `elasticapm.set_custom_context()`
 
+[small]#Added in v2.0.0.#
+
 Attach custom contextual data to the current transaction and errors.
 Supported frameworks will automatically attach information about the HTTP request and the logged in user.
 You can attach further data using this function.
@@ -369,6 +403,8 @@ following the `update()` semantics of Python dictionaries.
 [[api-set-user-context]]
 ==== `elasticapm.set_user_context()`
 
+[small]#Added in v2.0.0.#
+
 Attach information about the currently logged in user to the current transaction and errors.
 Example:
 
@@ -392,6 +428,8 @@ following the `update()` semantics of Python dictionaries.
 [[api-capture-span]]
 ==== `elasticapm.capture_span`
 
+[small]#Added in v4.1.0.#
+
 Capture a custom span.
 This can be used either as a function decorator or as a context manager (in a `with` statement).
 When used as a decorator, the name of the span will be set to the name of the function.
@@ -427,6 +465,8 @@ def coffee_maker(strength):
 [[api-async-capture-span]]
 ==== `elasticapm.async_capture_span`
 
+[small]#Added in v5.4.0.#
+
 Capture a custom async-aware span.
 This can be used either as a function decorator or as a context manager (in an `async with` statement).
 When used as a decorator, the name of the span will be set to the name of the function.
@@ -464,6 +504,8 @@ NOTE: `asyncio` is only supported for Python 3.7+.
 [[api-label]]
 ==== `elasticapm.label()`
 
+[small]#Added in v5.0.0.#
+
 Attach labels to the the current transaction and errors.
 
 TIP: Before using custom labels, ensure you understand the different types of