Adds DOCX and Markdown export functionality

Introduces a modular exporter pattern supporting DOCX and Markdown formats
by implementing Exporter interfaces and restructuring application logic.

Enhances CI to install UPX for binary compression, excluding recent macOS
binaries due to compatibility issues.

Enables CGO when building binaries for all platforms, addressing potential
cross-platform compatibility concerns.

Bumps version to 0.1.1.

internal/interfaces/parser.go

@@ -0,0 +1,20 @@
+// Package interfaces provides the core contracts for the articulate-parser application.
+// It defines interfaces for parsing and exporting Articulate Rise courses.
+package interfaces
+
+import "github.com/kjanat/articulate-parser/internal/models"
+
+// CourseParser defines the interface for loading course data.
+// It provides methods to fetch course content either from a remote URI
+// or from a local file path.
+type CourseParser interface {
+	// FetchCourse loads a course from a URI (typically an Articulate Rise share URL).
+	// It retrieves the course data from the remote location and returns a parsed Course model.
+	// Returns an error if the fetch operation fails or if the data cannot be parsed.
+	FetchCourse(uri string) (*models.Course, error)
+
+	// LoadCourseFromFile loads a course from a local file.
+	// It reads and parses the course data from the specified file path.
+	// Returns an error if the file cannot be read or if the data cannot be parsed.
+	LoadCourseFromFile(filePath string) (*models.Course, error)
+}