move contributing guide to the repo

CONTRIBUTING.md

@@ -0,0 +1,62 @@
+# Contributing
+
+Code contributions are always welcomed in lf.
+
+If you are going to introduce a new feature, it is best to open an issue first for discussion. If your feature can be implemented as a configuration option **please add it to the [wiki](https://github.com/gokcehan/lf/wiki)**.
+
+For bug fixes, you can simply send a pull request.
+
+## Code conventions
+
+In addition to `gofmt` and friends (e.g. [go vet](https://pkg.go.dev/cmd/vet), [staticcheck](https://staticcheck.dev/), [golangci-lint](https://golangci-lint.run/)), we have a few conventions:
+
+- Global variables are best avoided except when they are not.
+Global variable names are prefixed with `g` as in `gFooBar`.
+Exceptions are variables holding values of environmental variables which are prefixed with `env` as in `envFooBar` and regular expressions which are prefixed with `re` as in `reFooBar` when they are global.
+- Type and function names are small case as in `fooBar` since we don't use exporting.
+- For file name variables, `name`, `fname`, or `filename` should refer to the base name of the file as in `baz.txt`, and `path`, `fpath`, or `filepath` should refer to the full path of the file as in `/foo/bar/baz.txt`.
+- Run `go fmt && go generate` using Go 1.19+. On earlier versions of Go, `go generate` creates needless whitespace differences.
+
+Use the surrounding code as reference when in doubt as usual.
+
+## Adding a new option
+
+Adding a new option usually requires the following steps:
+
+- Add option name/type to `gOpts` struct in `opts.go`
+- Add default option value to `init` function in `opts.go`
+- Add option evaluation logic to `setExpr.eval` in `eval.go`
+- Implement the option somewhere in the code
+- Add option name to `gOptWords` in `complete.go` for tab completion
+- Add option name and its default value to `Quick Reference` and `Options` sections in `doc.go`
+- Run `go generate` to update the documentation
+- Commit your changes and send a pull request
+
+## Adding a new builtin command
+
+Adding a new command usually requires the following steps:
+
+- Add default key if any to `init` function in `opts.go`
+- Add command evaluation logic to `callExpr.eval` in `eval.go`
+- Implement the command somewhere in the code
+- Add command name to `gCmdWords` in `complete.go` for tab completion
+- Add command name to `Quick Reference` and `Commands` sections in `doc.go`
+- Run `go generate` to update the documentation
+- Commit your changes and send a pull request
+
+## Platform specific code
+
+There are two files named `os.go` and `os_windows.go` for unix and windows specific code respectively.
+If you add something to either of these files but not the other, you probably break the build for the other platform.
+If your addition works the same in both platforms, your addition probably belongs to `main.go` instead.
+
+## Make changes to the documentation
+
+There are three files that contain the documentation in various formats:
+
+- `doc.go` is the source of the [online documentation](https://pkg.go.dev/github.com/gokcehan/lf)
+- `docstring.go` is used when running `lf -doc`
+- `lf.1` is a man page which is commonly available on Unix-like operating systems (`man lf`)
+
+You should only make changes to `doc.go`, the other files are automatically generated **and should not be edited manually**.
+Run `go fmt && go generate` to ensure that the code is formatted and files are generated correctly.

README.md

@@ -77,4 +77,4 @@ See [tips](https://github.com/gokcehan/lf/wiki/Tips) for more examples.
 
 ## Contributing
 
-See [contributing](https://github.com/gokcehan/lf/wiki/Contributing) for guidelines.
+See [contributing](CONTRIBUTING.md) for guidelines.