Support 3.0.0 build in makefile and document makefile usage #49

	name: Build

	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	build:
	name: Generate code

	runs-on: ubuntu-latest

	strategy:
	matrix:
	language:
	- java
	- javascript
	- python
	- modernpython
	- cpp

	schema:
	- CGMES_2.4.15_27JAN2020
	- CGMES_3.0.0

	steps:
	- name: Checkout repo
	uses: actions/checkout@v4

	- name: Setup Python
	uses: actions/setup-python@v5
	with:
	python-version: '3.11'

	- name: Generate code
	run: \|
	python -m venv venv
	. venv/bin/activate

	pip install .

	# Extract version (2.4.15 => 2_4_15), ignore the date part
	SCHEMA_VERSION=$(echo "${{matrix.schema}}" \| cut -d'_' -f2 \| cut -d'.' -f1-3 \| tr '.' '_')

	# Run cimgen with the valid version
	cimgen \
	--outdir=output/${{matrix.language}}/${{matrix.schema}} \
	--schemadir=cgmes_schema/${{matrix.schema}} \
	--langdir=${{matrix.language}} \
	--cgmes_version=cgmes_v${SCHEMA_VERSION}

	- name: Create artifact
	uses: actions/upload-artifact@v4
	with:
	name: ${{matrix.schema}}-${{matrix.language}}
	path: output/${{matrix.language}}

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