Update cheatsheets

gofmt

@@ -0,0 +1,25 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# gofmt
+
+> Format Go source code.
+> More information: <https://golang.org/cmd/gofmt/>.
+
+- Format a file and display the result to the console:
+
+`gofmt {{source.go}}`
+
+- Format a file, overwriting the original file in-place:
+
+`gofmt -w {{source.go}}`
+
+- Format a file, and then simplify the code, overwriting the original file:
+
+`gofmt -s -w {{source.go}}`
+
+- Print all (including spurious) errors:
+
+`gofmt -e {{source.go}}`