Adding upstream version 2.6.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

README.md

@@ -0,0 +1,151 @@
+![Build Status](https://github.com/editorconfig/editorconfig-core-go/workflows/.github/workflows/main.yml/badge.svg)
+[![Go Reference](https://pkg.go.dev/badge/github.com/editorconfig/editorconfig-core-go/v2.svg)](https://pkg.go.dev/github.com/editorconfig/editorconfig-core-go/v2)
+[![Go Report Card](https://goreportcard.com/badge/github.com/editorconfig/editorconfig-core-go)](https://goreportcard.com/report/github.com/editorconfig/editorconfig-core-go)
+
+# Editorconfig Core Go
+
+A [Editorconfig][editorconfig] file parser and manipulator for Go.
+
+## Missing features
+
+- escaping comments in values, probably in [go-ini/ini](https://github.com/go-ini/ini)
+- [adjacent nested braces](https://github.com/editorconfig/editorconfig-core-test/pull/44)
+
+## Installing
+
+We recommend the use of Go 1.17+ modules for this package. Lower versions, such as 1.13, should be fine.
+
+Import by the same path. The package name you will use to access it is
+`editorconfig`.
+
+```go
+import "github.com/editorconfig/editorconfig-core-go/v2"
+```
+
+## Usage
+
+### Parse from a file
+
+```go
+fp, err := os.Open("path/to/.editorconfig")
+if err != nil {
+	log.Fatal(err)
+}
+defer fp.Close()
+
+editorConfig, err := editorconfig.Parse(fp)
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+### Graceful parsing from a file
+
+```go
+fp, err := os.Open("path/to/.editorconfig")
+if err != nil {
+	log.Fatal(err)
+}
+defer fp.Close()
+
+editorConfig, warning, err := editorconfig.ParseGraceful(fp)
+if err != nil {
+	log.Fatal(err)
+}
+
+// Log the warning(s) encountered while reading the editorconfig file
+if warning != nil {
+	log.Print(warning)
+}
+```
+
+### Parse from slice of bytes
+
+```go
+data := []byte("...")
+editorConfig, err := editorconfig.ParseBytes(data)
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+### Get definition to a given filename
+
+This method builds a definition to a given filename.
+This definition is a merge of the properties with selectors that matched the
+given filename.
+The lasts sections of the file have preference over the priors.
+
+```go
+def := editorConfig.GetDefinitionForFilename("my/file.go")
+```
+
+This definition have the following properties:
+
+```go
+type Definition struct {
+	Selector string
+
+	Charset                string
+	IndentStyle            string
+	IndentSize             string
+	TabWidth               int
+	EndOfLine              string
+	TrimTrailingWhitespace *bool
+	InsertFinalNewline     *bool
+	Raw                    map[string]string
+}
+```
+
+#### Automatic search for `.editorconfig` files
+
+If you want a definition of a file without having to manually
+parse the `.editorconfig` files, you can then use the static version
+of `GetDefinitionForFilename`:
+
+```go
+def, err := editorconfig.GetDefinitionForFilename("foo/bar/baz/my-file.go")
+```
+
+In the example above, the package will automatically search for
+`.editorconfig` files on:
+
+- `foo/bar/baz/.editorconfig`
+- `foo/baz/.editorconfig`
+- `foo/.editorconfig`
+
+Until it reaches a file with `root = true` or the root of the filesystem.
+
+### Generating a .editorconfig file
+
+You can easily convert a Editorconfig struct to a compatible INI file:
+
+```go
+// serialize to slice of bytes
+data, err := editorConfig.Serialize()
+if err != nil {
+	log.Fatal(err)
+}
+
+// save directly to file
+err := editorConfig.Save("path/to/.editorconfig")
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+## Contributing
+
+To run the tests:
+
+```bash
+go test -v ./...
+```
+
+To run the [integration tests](https://github.com/editorconfig/editorconfig-core-test):
+
+```bash
+make test-core
+```
+
+[editorconfig]: https://editorconfig.org/