feat: feat: add options.validator, getValidator, setValidator

`Atom.of` now takes an optional `options` dictionary, which accepts a `validator` predicate function
that will validate Atom state at initialization, `swap`, and `set`. `validator` is `() => true` by
default. An atom's validator function can be also be set after initialization with `setValidator`.
And atom's validator can be accessed with `getValidator`.

docs/classes/atom.html

@@ -65,15 +65,11 @@ <h1>Class Atom&lt;S&gt;</h1>
 			<section class="tsd-panel tsd-comment">
 				<div class="tsd-comment tsd-typography">
 					<div class="lead">
-						<p><code>@libre/atom</code> provides a data type called <code>Atom</code> and a few functions for working with <code>Atom</code>s.
-						It is heavily inspired by <code>atom</code>s in Clojure(Script).</p>
+						<p>A data structure useful for providing a controlled, predictable mechanism for mutability.
+							Allows multiple components of a program to share read/write access to some state in such
+							a way that no component can mutate another component&#39;s current reference to the state in
+						the middle of some process or asynchronous operation.</p>
 					</div>
-					<p>Atoms provide a predictable way to manage state that is shared by multiple components of a
-						program as that state changes over time. They are particularly useful in the functional and reactive
-						programming paradigms, where most components of a program are pure functions operating on
-						immutable data. In this context, Atoms provide a form of mutability that is controlled in such
-						a way that no component can mutate another component&#39;s current reference to the state in
-					the middle of some process or asynchronous operation.</p>
 				</div>
 			</section>
 			<section class="tsd-panel tsd-type-parameters">
@@ -111,13 +107,13 @@ <h2>Methods</h2>
 					<a name="of" class="tsd-anchor"></a>
 					<h3><span class="tsd-flag ts-flagStatic">Static</span> of</h3>
 					<ul class="tsd-signatures tsd-kind-method tsd-parent-kind-class tsd-has-type-parameter tsd-is-static">
-						<li class="tsd-signature tsd-kind-icon">of&lt;S&gt;<span class="tsd-signature-symbol">(</span>state<span class="tsd-signature-symbol">: </span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">)</span><span class="tsd-signature-symbol">: </span><a href="atom.html" class="tsd-signature-type">Atom</a><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">&gt;</span></li>
+						<li class="tsd-signature tsd-kind-icon">of&lt;S&gt;<span class="tsd-signature-symbol">(</span>state<span class="tsd-signature-symbol">: </span><span class="tsd-signature-type">S</span>, options<span class="tsd-signature-symbol">?: </span><a href="../interfaces/atomconstructoroptions.html" class="tsd-signature-type">AtomConstructorOptions</a><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">&gt;</span><span class="tsd-signature-symbol">)</span><span class="tsd-signature-symbol">: </span><a href="atom.html" class="tsd-signature-type">Atom</a><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">&gt;</span></li>
 					</ul>
 					<ul class="tsd-descriptions">
 						<li class="tsd-description">
 							<aside class="tsd-sources">
 								<ul>
-									<li>Defined in atom.ts:53</li>
+									<li>Defined in atom.ts:50</li>
 								</ul>
 							</aside>
 							<div class="tsd-comment tsd-typography">
@@ -150,6 +146,9 @@ <h4 class="tsd-parameters-title">Parameters</h4>
 								<li>
 									<h5>state: <span class="tsd-signature-type">S</span></h5>
 								</li>
+								<li>
+									<h5><span class="tsd-flag ts-flagOptional">Optional</span> options: <a href="../interfaces/atomconstructoroptions.html" class="tsd-signature-type">AtomConstructorOptions</a><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">&gt;</span></h5>
+								</li>
 							</ul>
 							<h4 class="tsd-returns-title">Returns <a href="atom.html" class="tsd-signature-type">Atom</a><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">S</span><span class="tsd-signature-symbol">&gt;</span></h4>
 						</li>
@@ -179,6 +178,9 @@ <h4 class="tsd-returns-title">Returns <a href="atom.html" class="tsd-signature-t
 					</li>
 				</ul>
 				<ul class="after-current">
+					<li class=" tsd-kind-interface tsd-has-type-parameter">
+						<a href="../interfaces/atomconstructoroptions.html" class="tsd-kind-icon">Atom<wbr>Constructor<wbr>Options</a>
+					</li>
 					<li class=" tsd-kind-type-alias tsd-has-type-parameter">
 						<a href="../globals.html#atomstate" class="tsd-kind-icon">Atom<wbr>State</a>
 					</li>
@@ -188,9 +190,15 @@ <h4 class="tsd-returns-title">Returns <a href="atom.html" class="tsd-signature-t
 					<li class=" tsd-kind-function tsd-has-type-parameter">
 						<a href="../globals.html#deref" class="tsd-kind-icon">deref</a>
 					</li>
+					<li class=" tsd-kind-function tsd-has-type-parameter">
+						<a href="../globals.html#getvalidator" class="tsd-kind-icon">get<wbr>Validator</a>
+					</li>
 					<li class=" tsd-kind-function tsd-has-type-parameter">
 						<a href="../globals.html#set" class="tsd-kind-icon">set</a>
 					</li>
+					<li class=" tsd-kind-function tsd-has-type-parameter">
+						<a href="../globals.html#setvalidator" class="tsd-kind-icon">set<wbr>Validator</a>
+					</li>
 					<li class=" tsd-kind-function tsd-has-type-parameter">
 						<a href="../globals.html#swap" class="tsd-kind-icon">swap</a>
 					</li>