Improve docker image

Change-Id: I4e0767497b019e70512e2c7962360f6b0a318658
diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..79a0047
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,17 @@
+termmapper
+.git
+*.tmp
+*.log
+# Include all Go source files and directories
+!*.go
+!cmd/
+!config/
+!parser/
+!ast/
+!mapper/
+!matcher/
+!mappings/
+!/LICENSE
+!.dockerignore
+!go.mod
+!go.sum
\ No newline at end of file