[ADF-4152] Updated folder structure of core docs (#4415)

* [ADF-4152] Moved core library docs into subfolders

* [ADF-4152] Moved core library docs into subfolders

* [ADF-4152] Manual fixes to core doc file links

* [ADF-4152] Further automatic + manual link tidying

docs/core/components/text-mask.component.md

@@ -0,0 +1,71 @@
+---
+Title: Text Mask directive
+Added: v2.0.0
+Status: Active
+Last reviewed: 2018-11-20
+---
+
+# [Text Mask directive](../../../lib/core/form/components/widgets/text/text-mask.component.ts "Defined in text-mask.component.ts")
+
+Implements text field input masks.
+
+## Basic Usage
+
+```html
+<input [textMask]="{mask: mask, isReversed: isMaskReversed}">
+```
+
+## Class members
+
+### Properties
+
+| Name | Type | Default value | Description |
+| ---- | ---- | ------------- | ----------- |
+| inputMask | `Function` |  | Object defining mask and "reversed" status. |
+
+## Details
+
+The Text Mask directive implements the "input mask" feature defined in the
+Process Services form editor. The mask restricts the way that text data can
+be added to the field and also adds formatting as you type. A common example of
+this feature is seen in text boxes that accept credit card numbers. The number is
+printed on the card as groups of four digits separated by spaces:
+
+`1234 5678 9012 3456`
+
+When you type into the field, you can only enter digits and spaces (spaces
+are only valid if you type them in the position they occur in the mask;
+otherwise, they are added automatically as you type digits). The equivalent
+text mask in ADF would be:
+
+`0000 0000 0000 0000`
+
+### Mask format characters
+
+The following characters have special meaning within a mask; all other characters
+are included in the text as they are:
+
+-   **"0"**: Denotes a digit
+-   **"9"**: Denotes a digit that can optionally be left out
+-   **"A"**: Denotes a alphanumeric character (upper- or lower-case A-Z and digits 0-9)
+-   **"S"**: Denotes a alphabetic character (upper- or lower-case A-Z)
+-   **"#"**: Denotes a string of zero or more digits
+
+The mask is passed to the directive in the `mask` field of the parameter object. The
+`reversed` field indicates that digits in the mask are "filled up" in
+right-to-left order rather than the usual left-to-right. For example, with the
+following mask:
+
+`#0.0`
+
+...if the user typed the digits "23" in sequence, the normal left-to-right ordering
+would show
+
+`23`
+
+...in the textbox. To get the decimal point, the user would have to type it explicitly.
+However, with reversed (right-to-left) ordering, the textbox would show
+
+`2.3`
+
+...and these digits would slide leftward as the user typed more.