Redo shield, removing FPGA

Don't have the FPGA on the shield, just have it be a board that plugs
into the FPGA.

Don't mind the component and footprint choices yet, I still need to
figure out exactly which parts to use.

hw/efinix_shield/.gitignore

@@ -0,0 +1,29 @@
+# For PCBs designed using KiCad: https://www.kicad.org/
+# Format documentation: https://kicad.org/help/file-formats/
+
+# Temporary files
+*.000
+*.bak
+*.bck
+*.kicad_pcb-bak
+*.kicad_sch-bak
+*-backups
+*.kicad_prl
+*.sch-bak
+*~
+_autosave-*
+*.tmp
+*-save.pro
+*-save.kicad_pcb
+fp-info-cache
+
+# Netlist files (exported from Eeschema)
+*.net
+
+# Autorouter files (exported from Pcbnew)
+*.dsn
+*.ses
+
+# Exported BOM files
+*.xml
+*.csv