docs: Removed and purged uneeded docs. (#2273)

docs/backend/xl/README.md

@@ -0,0 +1,54 @@
+### Backend format `xl.json`
+
+```go
+// objectPartInfo Info of each part kept in the multipart metadata
+// file after CompleteMultipartUpload() is called.
+type objectPartInfo struct {
+	Number int    `json:"number"`
+	Name   string `json:"name"`
+	ETag   string `json:"etag"`
+	Size   int64  `json:"size"`
+}
+
+// checkSumInfo - carries checksums of individual scattered parts per disk.
+type checkSumInfo struct {
+	Name      string `json:"name"`
+	Algorithm string `json:"algorithm"`
+	Hash      string `json:"hash"`
+}
+
+// erasureInfo - carries erasure coding related information, block
+// distribution and checksums.
+type erasureInfo struct {
+	Algorithm    string         `json:"algorithm"`
+	DataBlocks   int            `json:"data"`
+	ParityBlocks int            `json:"parity"`
+	BlockSize    int64          `json:"blockSize"`
+	Index        int            `json:"index"`
+	Distribution []int          `json:"distribution"`
+	Checksum     []checkSumInfo `json:"checksum,omitempty"`
+}
+
+// statInfo - carries stat information of the object.
+type statInfo struct {
+	Size    int64     `json:"size"`    // Size of the object `xl.json`.
+	ModTime time.Time `json:"modTime"` // ModTime of the object `xl.json`.
+}
+
+// A xlMetaV1 represents `xl.json` metadata header.
+type xlMetaV1 struct {
+	Version string   `json:"version"` // Version of the current `xl.json`.
+	Format  string   `json:"format"`  // Format of the current `xl.json`.
+	Stat    statInfo `json:"stat"`    // Stat of the current object `xl.json`.
+	// Erasure coded info for the current object `xl.json`.
+	Erasure erasureInfo `json:"erasure"`
+	// Minio release tag for current object `xl.json`.
+	Minio struct {
+		Release string `json:"release"`
+	} `json:"minio"`
+	// Metadata map for current object `xl.json`.
+	Meta map[string]string `json:"meta,omitempty"`
+	// Captures all the individual object `xl.json`.
+	Parts []objectPartInfo `json:"parts,omitempty"`
+}
+```

docs/backend/xl/xl.json

@@ -16,7 +16,7 @@
     "meta": {
         "md5Sum": "97586a5290d4f5a41328062d6a7da593-3",
         "content-type": "application\/octet-stream",
-        "content-encoding": ""
+        "content-encoding": "gzip"
     },
     "minio": {
         "release": "DEVELOPMENT.GOGET"