added contribution guideline

Author: CodingSamrat

CONTRIBUTING.md

@@ -0,0 +1,50 @@
+# Contributing Guidelines
+
+Thank you for investing your time in contributing to our project! Whether it's a bug report, new feature, correction, or additional documentation, we greatly value feedback and contributions from our community. Any contribution you make will be reflected on `github.com/FileXdb/FileXdb-Python`✨.
+
+Contributions to _FileXdb_ are welcome! Here's how to get started:
+
+- Open an [issue](https://github.com/FileXdb/FileXdb-Python/issues) or find for related issues to start a discussion around a feature idea or a bug.
+- Fork the [repository](https://github.com/FileXdb/FileXdb-Python) on GitHub.
+- Create a new branch of the master branch and start making your changes.
+- Make a meaning-full commit.
+- Write a test, which shows that the bug is fixed or the feature works as expected.
+- Send a pull request and wait until it gets merged and published.
+
+
+
+# Coding Conventions
+
+In general the FileXdb source code always follows [PEP 8](http://legacy.python.org/dev/peps/pep-0008/).
+Exceptions are allowed in well justified and documented cases. However, we make
+a small exception concerning docstrings:
+
+When using multiline docstrings, keep the opening and closing triple quotes
+on their own lines and add an empty line after it. 
+
+Here is a demo for you.
+
+```python
+
+    def sum_of_two_num(a: int, b: int ) -> int:
+        """
+        Documentation ...
+        
+        :param a: Definition...
+        :param b: Definition...
+        :return: Definition...
+        """
+        
+        # Implementation Documentation ...
+        result = a + b
+        
+        return result
+```
+
+
+
+# Version Numbers
+
+FileXdb follows the [SemVer versioning guidelines](http://semver.org).
+This implies that backwards incompatible changes in the API will increment
+the major version. So think twice before making such changes.