Add multi_ch_cal modules, optimize .gitignore.

projects/.gitignore

@@ -0,0 +1,67 @@
+# ---------------------------- Vivado & SDK common -----------------------------
+
+# ignore the vivado project
+*/*/project/*/*
+
+#  folders (and all of their contents) that should always be ignored,
+#  anywhere in the repo
+.Xil/
+
+#  file patterns that should always be ignored (journal files, log
+#  files, dump files that are created upon Vivado/SDK errors)
+*.jou
+*.log
+*.backup.jou
+*.backup.log
+*.upgrade_log
+*.dmp
+vivado_pid*
+*~
+
+# ------------------------------ Vivado Specific -------------------------------
+
+# preserve project tcl
+!/*/*/project/*/*.tcl
+
+# preserve hardware manager projects and sources
+!*/*/project/*/*.hw/
+
+# preserve design run results
+!*/*/project/*/*.runs/
+*/*/project/*/*.runs/*
+!*/*/project/*/*.runs/impl_*/
+*/*/project/*/*.runs/impl_*/*
+!*/*/project/*/*.runs/impl_*/*.bit
+!*/*/project/*/*.runs/impl_*/*.ltx
+
+# -------------------------------- SDK Specific --------------------------------
+!*/*/project/*/*.sdk/
+
+# exclude some obscure hidden SDK folders
+*/*/project/*/*.sdk/.metadata/
+*/*/project/*/*.sdk/.sdk/
+*/*/project/*/*.sdk/RemoteSystemsTempFiles/
+*/*/project/*/*.sdk/webtalk/
+
+# hw_platform : exclude the entire hw_platform folder, as everything can be
+# generated from the .hdf file. Make sure to include the bitstream in the .hdf
+# file when exporting from Vivado!
+*/*/project/*/*.sdk/*_hw_platform_*/
+
+# BSP: only keep `.cproject`, `.project`, `.sdkproject`, `.system.mss` and
+# Makefile, the ps7_cortexa9_0 lib files are regenerated automatically
+*/*/project/*/*.sdk/*_bsp/*
+!*/*/project/*/*.sdk/*_bsp/*.cproject
+!*/*/project/*/*.sdk/*_bsp/*.project
+!*/*/project/*/*.sdk/*_bsp/*.sdkproject
+!*/*/project/*/*.sdk/*_bsp/system.mss
+!*/*/project/*/*.sdk/*_bsp/Makefile
+
+# Application: ignored file patterns, exclude Debug & Release folders
+*/*/project/*/*.sdk/**/*.o
+*/*/project/*/*.sdk/**/*.d
+*/*/project/*/*.sdk/**/*.a
+*/*/project/*/*.sdk/*/Debug/
+*/*/project/*/*.sdk/*/Release/
+
+# REF: https://support.xilinx.com/s/question/0D52E00006iHpHzSAK/which-files-and-folders-of-an-sdk-project-should-be-checked-into-git-and-which-ones-should-be-ignored?language=en_US