initSpecVersionFromFile method
Initialize the SpecVersions from a Json file path containing spec-versions
After reading Spec Versions then it calls addSpecVersion(spec)
with spec being the parsed Spec from file.
Implementation
void initSpecVersionFromFile(String filePath) {
final list = readSpecVersionsFromFilePath(filePath);
for (var spec in list) {
addSpecVersion(spec);
}
}