Add project's CI pipeline configuration

.gitlab-ci.yml

+image: node:latest
+
+stages:
+  - test
+  - doc
+
+before_script:
+  - npm install
+
+test:
+  stage: test
+  script:
+    - npm test
+
+doc:
+  stage: doc
+  artifacts:
+    paths:
+      - documentation/doc.md
+  script:
+    # Build documentation in md file that will be available from gitlab interface
+    - npm run docs:md

documentation/doc.md

+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+### Table of Contents
+
+-   [Compute][1]
+-   [add][2]
+    -   [Parameters][3]
+-   [sub][4]
+    -   [Parameters][5]
+
+## Compute
+
+Object containing the arithmetic operations
+
+## add
+
+Calculate the sum of two numbers
+
+### Parameters
+
+-   `a` **[Number][6]** First member of the operation
+-   `b` **[Number][6]** Second member of the operation
+
+Returns **[Number][6]** Sum of a and b
+
+## sub
+
+Calculate the difference between two numbers
+
+### Parameters
+
+-   `a` **[Number][6]** First member of the operation
+-   `b` **[Number][6]** Second member of the operation
+
+Returns **[Number][6]** Difference between a and b (a - b)
+
+[1]: #compute
+
+[2]: #add
+
+[3]: #parameters
+
+[4]: #sub
+
+[5]: #parameters-1
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number