Add an option to define the line count parsed for the signature check

internal/config/settings.go

@@ -52,6 +52,7 @@ var optionValidators = map[string]optionValidator{
 	"fileformat":   validateLineEnding,
 	"encoding":     validateEncoding,
 	"multiopen":    validateMultiOpen,
+	"detectlimit":  validateNonNegativeValue,
 }
 
 func ReadSettings() error {
@@ -315,6 +316,7 @@ var defaultCommonSettings = map[string]interface{}{
 	"tabstospaces":   false,
 	"useprimary":     true,
 	"wordwrap":       false,
+	"detectlimit":    float64(100),
 }
 
 func GetInfoBarOffset() int {

runtime/help/options.md

@@ -183,11 +183,11 @@ Here are the available options:
 	default value: `true`
 
 * `indentchar`: sets the indentation character. This will not be inserted into
-  files; it is only a visual indicator that whitespace is present. If set to a
-  printing character, it functions as a subset of the "show invisibles"
-  setting available in many other text editors. The color of this character is
-  determined by the `indent-char` field in the current theme rather than the
-  default text color.
+   files; it is only a visual indicator that whitespace is present. If set to a
+   printing character, it functions as a subset of the "show invisibles"
+   setting available in many other text editors. The color of this character is
+   determined by the `indent-char` field in the current theme rather than the
+   default text color.
 
 	default value: ` ` (space)
 
@@ -386,7 +386,7 @@ Here are the available options:
 	default value: `false`
 
 * `tabhighlight`: inverts the tab characters' (filename, save indicator, etc)
-  colors with respect to the tab bar.
+   colors with respect to the tab bar.
 
 	default value: false
 
@@ -398,6 +398,11 @@ Here are the available options:
 
 	default value: `4`
 
+* `detectlimit`: if this is not set to 0, it will limit the automatic parsed
+   lines of files to the given value.
+
+   default value: `100`
+
 * `tabstospaces`: use spaces instead of tabs. Note: This option will be
    overridden by [the `ftoptions` plugin](https://github.com/zyedidia/micro/blob/master/runtime/plugins/ftoptions/ftoptions.lua)
    for certain filetypes. To disable this behavior, add `"ftoptions": false` to

runtime/syntax/README.md

@@ -2,7 +2,7 @@
 
 Here are micro's syntax files.
 
-Each yaml file specifies how to detect the filetype based on file extension or given signature. The signature can be matched to a maximum of 100 lines (to limit parse times) for a best "guess".
+Each yaml file specifies how to detect the filetype based on file extension or given signature. The signature can be matched to all available lines of the file or to the value defined with the option `detectlimit` (to limit parse times) for a best "guess".
 Then there are patterns and regions linked to highlight groups which tell micro how to highlight that filetype.
 
 Making your own syntax files is very simple. I recommend you check the file after you are finished with the