Improve documentation

Signed-off-by: Bastien <bastien.wermeille@gmail.com>

README.rst

@@ -1130,15 +1130,15 @@ Below is an example of publishing to Vault (using token auth with a local dev in
 Important information on types
 ------------------------------
 
-YAML and JSON type extensions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+YAML, JSON, ENV and INI type extensions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 SOPS uses the file extension to decide which encryption method to use on the file
 content. ``YAML``, ``JSON``, ``ENV``, and ``INI`` files are treated as trees of data, and key/values are
 extracted from the files to only encrypt the leaf values. The tree structure is also
 used to check the integrity of the file.
 
-Therefore, if a file is encrypted using a specific format, it need to be decrypted
+Therefore, if a file is encrypted using a specific format, it needs to be decrypted
 in the same format. The easiest way to achieve this is to conserve the original file
 extension after encrypting a file. For example:
 
@@ -1165,23 +1165,27 @@ When operating on stdin, use the ``--input-type`` and ``--output-type`` flags as
 JSON indentation
 ~~~~~~~~~~~~~~~~
 
-``sops`` indent ``SOPS`` files by default using one ``tab``. However, you can change
-this default behaviour to use spaces by either using the additional ``--indent=2`` cli option or
-by configuring ``.sops.yaml`` with the code below. (value ``0`` is no indentation)
+SOPS indents ``JSON`` files by default using one ``tab``. However, you can change
+this default behaviour to use ``spaces`` by either using the additional ``--indent=2`` CLI option or
+by configuring ``.sops.yaml`` with the code below.
+
+The special value ``0`` disables indentation, and ``-1`` uses a single tab.
 
 .. code:: yaml
+
   stores:
       json:
           indent: 2
 
 YAML indentation
 ~~~~~~~~~~~~~~~~
 
-``sops`` indent ``YAML`` files by default using 4 spaces. However, you can change
-this default behaviour by either using the additional ``--indent=2`` cli option or
-by configuring ``.sops.yaml`` with :
+SOPS indents ``YAML`` files by default using 4 spaces. However, you can change
+this default behaviour by either using the additional ``--indent=2`` CLI option or
+by configuring ``.sops.yaml`` with:
 
 .. code:: yaml
+
   stores:
       yaml:
           indent: 2

cmd/sops/main.go

@@ -706,7 +706,7 @@ func main() {
 		},
 		cli.IntFlag{
 			Name:  "indent",
-			Usage: "the number of space to indent YAML encoded file for encryption",
+			Usage: "the number of spaces to indent YAML or JSON encoded file for encryption",
 		},
 		cli.BoolFlag{
 			Name:  "verbose",
@@ -1087,7 +1087,7 @@ func inputStore(context *cli.Context, path string) common.Store {
 
 func outputStore(context *cli.Context, path string) common.Store {
 	storesConf, _ := loadStoresConfig(context, path)
-	if context.Int("indent") != 0 {
+	if context.IsSet("indent") {
 		indent := context.Int("indent")
 		storesConf.YAML.Indent = indent
 		storesConf.JSON.Indent = indent