docs: add missing modules to sphinx documentation build

Add RST files and toctree entries for modules that were not included
in the sphinx doc build:

API:
- opentelemetry._events (Events API)
- opentelemetry.attributes (Attributes utilities)
- opentelemetry.trace.propagation (Trace context propagation)

SDK:
- opentelemetry.sdk._events (Events SDK implementation)
- opentelemetry.sdk._logs.export (Log export processors and exporters)

Closes #2573

Signed-off-by: Raajhesh Kannaa Chidambaram <495042+raajheshkannaa@users.noreply.github.com>

Author: raajheshkannaa

docs/api/_events.rst

@@ -0,0 +1,10 @@
+opentelemetry._events package
+=============================
+
+Module contents
+---------------
+
+.. automodule:: opentelemetry._events
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/api/attributes.rst

@@ -0,0 +1,7 @@
+opentelemetry.attributes
+========================
+
+.. automodule:: opentelemetry.attributes
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/api/index.rst

@@ -14,7 +14,9 @@ For the concrete implementation of these interfaces, see the
 .. toctree::
     :maxdepth: 1
 
+    _events
     _logs
+    attributes
     baggage
     context
     propagate

docs/api/trace.propagation.rst

@@ -0,0 +1,7 @@
+opentelemetry.trace.propagation
+===============================
+
+.. automodule:: opentelemetry.trace.propagation
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/api/trace.rst

@@ -8,6 +8,7 @@ Submodules
 
    trace.status
    trace.span
+   trace.propagation
 
 Module contents
 ---------------

docs/sdk/_events.rst

@@ -0,0 +1,7 @@
+opentelemetry.sdk._events package
+=================================
+
+.. automodule:: opentelemetry.sdk._events
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/sdk/_logs.export.rst

@@ -0,0 +1,7 @@
+opentelemetry.sdk._logs.export
+==============================
+
+.. automodule:: opentelemetry.sdk._logs.export
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/sdk/_logs.rst

@@ -1,6 +1,16 @@
 opentelemetry.sdk._logs package
 ===============================
 
+Submodules
+----------
+
+.. toctree::
+
+   _logs.export
+
+Module contents
+---------------
+
 .. automodule:: opentelemetry.sdk._logs
     :members:
     :undoc-members:

docs/sdk/index.rst

@@ -14,6 +14,7 @@ processed, and exported.
 .. toctree::
     :maxdepth: 1
 
+    _events
     _logs
     resources
     trace