doc: add missing periods in documentation.md

PR-URL: #20469
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

doc/api/documentation.md

@@ -35,24 +35,22 @@ and in the process of being redesigned.
 The stability indices are as follows:
 
 ```txt
-Stability: 0 - Deprecated
-This feature is known to be problematic, and changes may be planned. Do
-not rely on it. Use of the feature may cause warnings to be emitted.
-Backwards compatibility across major versions should not be expected.
+Stability: 0 - Deprecated. This feature is known to be problematic, and changes
+may be planned. Do not rely on it. Use of the feature may cause warnings to be
+emitted. Backwards compatibility across major versions should not be expected.
 ```
 
 ```txt
-Stability: 1 - Experimental
-This feature is still under active development and subject to non-backwards
-compatible changes, or even removal, in any future version. Use of the feature
-is not recommended in production environments. Experimental features are not
-subject to the Node.js Semantic Versioning model.
+Stability: 1 - Experimental. This feature is still under active development and
+subject to non-backwards compatible changes, or even removal, in any future
+version. Use of the feature is not recommended in production environments.
+Experimental features are not subject to the Node.js Semantic Versioning model.
 ```
 
 ```txt
-Stability: 2 - Stable
-The API has proven satisfactory. Compatibility with the npm ecosystem
-is a high priority, and will not be broken unless absolutely necessary.
+Stability: 2 - Stable. The API has proven satisfactory. Compatibility with the
+npm ecosystem is a high priority, and will not be broken unless absolutely
+necessary.
 ```
 
 Caution must be used when making use of `Experimental` features, particularly