docs: add library examples for calendar, crm, subtasks, applications

Four new executable examples mirror the oo-cli subcommands at library level so
downstream Go consumers can see the typed API without reading the CLI wiring.
README table updated to list all examples.

Made-with: Cursor

examples/calendar/main.go

@@ -0,0 +1,62 @@
+// Package main shows how to list calendars and events, and create a new event
+// via the OnlyOffice Calendar API.
+//
+//	export ONLYOFFICE_URL="https://your-instance.onlyoffice.com"
+//	export ONLYOFFICE_USER="admin@example.com"
+//	export ONLYOFFICE_PASS="your-password"
+//	# optional: default calendar for AddEvent
+//	export ONLYOFFICE_CALENDAR_ID="42"
+//	go run ./examples/calendar
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+)
+
+func main() {
+	creds := onlyoffice.GetEnvironmentCredentials()
+	if creds.Url == "" {
+		fmt.Fprintln(os.Stderr, "ONLYOFFICE_URL is not set")
+		os.Exit(1)
+	}
+
+	client := onlyoffice.NewClient(creds)
+	client.SetDefaults(onlyoffice.GetEnvironmentDefaults())
+
+	ctx := context.Background()
+	start := time.Now().Format("2006-01-02")
+	end := time.Now().AddDate(0, 1, 0).Format("2006-01-02")
+
+	calendars, err := client.ListCalendars(ctx, start, end)
+	if err != nil {
+		log.Fatalf("list calendars: %v", err)
+	}
+	fmt.Printf("Calendars (%d):\n", len(calendars))
+	for _, cal := range calendars {
+		fmt.Printf("  - id=%v title=%v\n", cal["objectId"], cal["title"])
+	}
+
+	events, err := client.ListEvents(ctx, start, end)
+	if err != nil {
+		log.Fatalf("list events: %v", err)
+	}
+	fmt.Printf("\nEvents in [%s..%s]: %d\n", start, end, len(events))
+	for _, e := range events {
+		fmt.Printf("  - %v @ %v\n", e["title"], e["start"])
+	}
+
+	// Create demo event — uncomment to exercise.
+	// evStart := time.Now().Add(time.Hour).Format(time.RFC3339)
+	// evEnd := time.Now().Add(2 * time.Hour).Format(time.RFC3339)
+	// created, err := client.AddEvent(ctx, "", "Library demo", evStart, evEnd, "via examples/calendar", false)
+	// if err != nil {
+	// 	log.Fatalf("add event: %v", err)
+	// }
+	// fmt.Printf("created event id=%v\n", created["objectId"])
+}