Add examples

What's Changed

• Add call web api example by @devlights in #637
• Add basic/errs/error_join.go by @devlights in #638
• Add yaml three-dash example by @devlights in #639
• Add diff_trimright_trimsuffix.go by @devlights in #640
• Update go-yaml version by @devlights in #641
• Add byteop/cut_prefix_suffix.go by @devlights in #642
• Add strs/cut_prefix_suffix.go by @devlights in #643
• Add mod operator example by @devlights in #644
• Add struct_read_write.go by @devlights in #645
• Add examples (国民の祝日 CSV ファイルで遊ぶ) by @devlights in #646
• Add error_join_fmterrorf.go by @devlights in #647
• Add time_change_timezone.go by @devlights in #648
• Add time_format_datetime.go by @devlights in #649
• Add time_format_dataonly.go by @devlights in #650
• Add time_format_timeonly.go by @devlights in #651
• Add error_join_errorsas.go by @devlights in #652
• Update .gitpod.Dockerfile by @devlights in #653
• Add fileio sync and close example by @devlights in #654
• Add examples/basic/formatting/numbers.go by @devlights in #655
• Add examples/basic/floatop by @devlights in #656

Full Changelog: v0.5.0...v0.5.1