feat: Add Czech language (#1207)

frontend/app_flowy/packages/appflowy_editor/lib/l10n/intl_cz_CZ.arb

@@ -0,0 +1,35 @@
+{
+  "@@locale": "cs-CZ",
+  "bold": "Tučně",
+  "@bold": {},
+  "bulletedList": "Odrážkový seznam",
+  "@bulletedList": {},
+  "checkbox": "Zaškrtávací políčko",
+  "@checkbox": {},
+  "embedCode": "Vložit kód",
+  "@embedCode": {},
+  "heading1": "Nadpis 1",
+  "@heading1": {},
+  "heading2": "Nadpis 2",
+  "@heading2": {},
+  "heading3": "Nadpis 3",
+  "@heading3": {},
+  "highlight": "Zvýraznění",
+  "@highlight": {},
+  "image": "Obrázek",
+  "@image": {},
+  "italic": "Kurzíva",
+  "@italic": {},
+  "link": "Odkaz",
+  "@link": {},
+  "numberedList": "Číslovaný seznam",
+  "@numberedList": {},
+  "quote": "Citace",
+  "@quote": {},
+  "strikethrough": "Přeškrtnutí",
+  "@strikethrough": {},
+  "text": "Text",
+  "@text": {},
+  "underline": "Podtržení",
+  "@underline": {}
+}