Merge pull request #122 from froschdesign/hotfix/docs/83

Expand documentation in introduction and validators files

docs/book/introduction.md

@@ -1,10 +1,35 @@
 # Introduction
 
-`Laminas\I18n` comes with a complete translation suite which supports all major
+## Translation
+
+`Laminas\I18n` comes with a [complete translation](translation.md) suite which supports all major
 formats and includes popular features like plural translations and text domains.
 The Translator component is mostly dependency free, except for the fallback to a
-default locale, where it relies on the Intl PHP extension.
+default locale, where it relies on the `intl` PHP extension.
 
 The translator itself is initialized without any parameters, as any configuration
 to it is optional. A translator without any translations will actually do nothing
 but just return the given message IDs.
+
+## Filters and Validators
+
+The `Laminas\I18n` component also provides a [set of filters](filters/introduction.md) for normalizing and formatting.
+
+The component also provides a [set of validators](validators/introduction.md) for validating localized data.
+
+## View Helpers
+
+The `Laminas\I18n` component provides also a [set of view helpers](view-helpers/introduction.md) for formatting dates, times, numbers, currencies, and translating messages.
+
+## Based on PHP's `intl` extension
+
+The [`intl` extension](https://www.php.net/manual/book.intl.php) is a wrapper for the ICU library, which provides a lot of
+internationalization functions. The `intl` extension is a standard PHP extension, and is required for the `Laminas\I18n` component to work.
+
+The `intl` functions are used for locale detection, filtering and validating localized data, formatting localized data and more.
+These functions are used in:
+
+- Translator
+- Filters
+- Validators
+- View Helpers

docs/book/validators/date-time.md

@@ -3,7 +3,7 @@
 `Laminas\I18n\Validator\DateTime` allows you to determine if a given value **is a
 valid date, time or datetime**.
 Internally, PHP's `IntlDateFormatter` tries to create a date time for the given
-value.
+value and locale.
 
 ## Basic Usage
 

docs/book/validators/is-float.md

@@ -11,6 +11,8 @@ example, using English, you might write `1.5`, whereas in german you would write
 `Laminas\I18n\Validator\IsFloat` is able to validate such notations. However, it
 is limited to the locale you set.
 
+Internally, PHP's `NumberFormatter` (`ext/intl`) tries to create a formatted number for the given value and locale.
+
 ## Basic Usage
 
 ```php

docs/book/validators/is-int.md

@@ -13,6 +13,8 @@ validity of an integer value. In such cases, it doesn't simply strip the
 separator, but instead validates that the correct separator as defined by used
 locale.
 
+Internally, PHP's `NumberFormatter` (`ext/intl`) tries to create a formatted number for the given value and locale.
+
 ## Basic Usage
 
 ```php