Add landuse=flowerbed to landcover (#1661)

This adds `landuse=flowerbed` to landcover.

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Co-authored-by: Petra Duriancikova <petra.duriancikova@maptiler.com>

layers/landcover/style.json

@@ -137,6 +137,8 @@
           "#f5dcba",
           "farmland",
           "#eef0d5",
+          "flowerbed",
+          "#cdebb0",
           "forest",
           "#add19e",
           "grass",
@@ -201,6 +203,7 @@
           "scrub",
           "farm",
           "farmland",
+          "flowerbed",
           "forest",
           "garden",
           "grass",
@@ -275,6 +278,8 @@
           "wetland_bog",
           "scrub",
           "scrub",
+          "flowerbed",
+          "flowerbed_high_zoom",
           "forest",
           "leaftype_unknown",
           "garden",
@@ -320,6 +325,7 @@
           "scrub",
           "farm",
           "farmland",
+          "flowerbed",
           "forest",
           "garden",
           "grass",