v0.0.64

• Added new OllamaChat::Tools::GetJiraIssue tool for fetching JIRA issue
  information
• Introduced ConfigMissingError exception for handling missing configuration
• Added JIRA tool configuration in OllamaChat::EnvConfig with URL, USER,
  and API_TOKEN settings
• Updated default_config.yml to include get_jira_issue tool with default: false
• Enhanced OllamaChat::Utils::Fetcher to support additional options and
  middleware
• Added comprehensive tests for the new get_jira_issue tool in
  spec/ollama_chat/tools/get_jira_issue_spec.rb
• Updated tool registration to include the new get_jira_issue tool