Add Copilot agent instructions (#744)

Author: knopers8

.github/copilot-instructions.md

@@ -0,0 +1,17 @@
+## ALICE Experiment Control System (AliECS)
+
+The ALICE Experiment Control System (**AliECS**) is the piece of software to drive and control data taking activities in the experiment.
+It is a distributed system that combines state of the art cluster resource management and experiment control functionalities into a single comprehensive solution.
+
+### Copilot agent instructions
+
+- Running `make` in the main directory lets you build all golang components of AliECS.
+- Running `make test` in the main directory lets you run all golang tests of AliECS.
+- Do not attempt to build C++ components unless you already have access to their dependencies (FairMQ and FairLogger) and the task requires you to do it.
+- When changing API interfaces, run `make docs` to regenerate the API documentation.
+- When changing gRPC interfaces and proto files, run `make generate` to regenerate the gRPC code.
+- Do not include regenerated Go files in your commits unless you are changing the API or proto files. If you do, include only the files which are related to your task.
+- Do not include modified go.mod and go.sum files in your commits unless you are adding or upgrading a dependency.
+- When adding features or fixing bugs, add a corresponding unit test if feasible. Use Ginkgo/Gomega, unless a package already uses a different testing framework.
+- When adding a new feature, extend the documentation accordingly, follow the existing style and structure, and make sure that Tables of Contents are updated. See [Documentation guidelines](docs/CONTRIBUTING.md#documentation-guidelines) for some more details.
+- When providing a fix, explain what was causing the issue and how it was fixed.

docs/CONTRIBUTING.md

@@ -51,7 +51,7 @@ Gomega/Ginkgo tests are preferred, but other style of tests are also welcome.
 ## Documentation guidelines
 
 The markdown documentation is aimed to be browsed on GitHub, but it also on the aggregated [FLP documentation](https://alice-flp.docs.cern.ch) based on [MkDocs](https://www.mkdocs.org/).
-Consequently, any changes in the documentation structure should be reflected in the Table of Contents in the main README.md, as well as `mkdocs.yml` and `mkdocs.yml`.
+Consequently, any changes in the documentation structure should be reflected in the Table of Contents in the main README.md, as well as `mkdocs.yml` and `mkdocs-dev.yml`.
 
 The AliECS MkDocs documentation is split into two aforementioned files to follow the split between "Products" and "Developers" tabs in the FLP documentation.
 The `mkdocs-dev.yml` uses a symlink `aliecs-dev` to `aliecs` directory to avoid complaints about duplicated site names.