Add GO26 medium adult field (#772)

Author: texhnolyze

src/bitbots_misc/bitbots_parameter_blackboard/config/fields/adult_go26/config.yaml

@@ -0,0 +1,19 @@
+############################
+# RoboCup German Open 2026 #
+############################
+
+# Settings for the RoboCup German Open 2026 field (with large goals)
+
+parameter_blackboard:
+  ros__parameters:
+    field:
+      size:
+        x: 14.0
+        y: 9.0
+        padding: 1.0   # Padding (area outside of the lines) of the field in all directions
+      markings:
+        penalty_area:
+          size:
+            x: 3.0   # The distance from the goal line to the boundary of the penalty area
+      goal:
+        width: 2.6   # The width of the goal (center of one goal post to the other goal post)

src/bitbots_misc/bitbots_parameter_blackboard/config/fields/adult_go26/gui-config.yaml

@@ -0,0 +1,29 @@
+# Map Generator Config
+# This file was generated by the map generator GUI
+
+header:
+  version: '1.0'
+  type: map_generator_config
+parameters:
+  map_type: line
+  penalty_mark: true
+  center_point: true
+  goal_back: true
+  stroke_width: 7
+  field_length: 1400
+  field_width: 900
+  goal_depth: 60
+  goal_width: 260
+  goal_area_length: 100
+  goal_area_width: 400
+  penalty_mark_distance: 210
+  center_circle_diameter: 300
+  border_strip_width: 100
+  penalty_area_length: 300
+  penalty_area_width: 600
+  field_feature_size: 28
+  mark_type: cross
+  field_feature_style: exact
+  distance_map: true
+  distance_decay: 0.0
+  invert: true