changelog: Add placeholder directory to add the changelogs

Signed-off-by: Sayan Chowdhury <schowdhury@microsoft.com>

changelog/README.md

@@ -0,0 +1,22 @@
+The `changelog` directory contains the description of the changes introduced
+into the repository.  The changes are essentially divided into 4 categories:
+- changes: PRs bringing Changes and/or Enhancements
+- bugfixes: PRs fixing existing issues
+- security: PRs fixing security issues
+- updates: PRs updating packages
+
+## How to add the file
+
+Based on the category the PR falls into create a new file in the respective
+directory with the filename format `DD-MM-YYYY-<few-words-about-the-change>.md`
+(can be generated via: `$(date '+%d-%m-%Y')-<few-words-about-the-change>.md`)
+
+The contents of the file should describe the changes in an elaborative manner
+(use the past tense for the change/bugfix description to avoid confusion with
+the imperative voice for actions the user should do as a result). Security
+fixes of upstream packages and package updates can be kept short in most cases
+and follow a standard format.
+
+As `Updates` refer to the package updates, the description of the file should
+be of the following format: `Package Name [Version](link to changelog)`
+Example: `Linux ([5.10.77](https://lwn.net/Articles/874852/))`