Auto merge of #23049 - dollinad:master, r=jdm

Edit Selector Implementation to be concise

Edit Selector Implementation in order to be concise.

Changes involve:
- Sentence rewrites
- Removal of dead links
- Correction of grammar and spelling

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #___ (GitHub issue number if applicable)

<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _changes were made to docs file only__

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/23049)
<!-- Reviewable:end -->

docs/components/style.md

@@ -1,22 +1,21 @@
 # Servo's style system overview
 
-This needs to be filled more extensively. Meanwhile, you can also take a look to
+This needs to be filled more extensively. Meanwhile, you can also take a look at
 the [style doc comments][style-doc], or the [Styling
-Overview][wiki-styling-overview] in the wiki, which is a conversation between
+Overview][wiki-styling-overview] in the wiki, a conversation between
 Boris Zbarsky and Patrick Walton about how style sharing works.
 
 <a name="selector-impl"></a>
 ## Selector Implementation
 
-The style system is generic over quite a few things, in order to be shareable
+In order to be sharable and compatible with [Stylo][stylo](a project that aims 
-with Servo's layout system, and with [Stylo][stylo], an ambitious project that
+to integrate Servo's style system into Gecko), the style must be consistent.
-aims to integrate Servo's style system into Gecko.
 
-The main generic trait is [selectors' SelectorImpl][selector-impl], that has all
+The consistency is implemented in [selectors' SelectorImpl][selector-impl], 
-the logic related to parsing pseudo-elements and other pseudo-classes appart
+containing the logic related to parsing pseudo-elements and other pseudo-classes 
-from [tree-structural ones][tree-structural-pseudo-classes].
+apart from [tree-structural ones][tree-structural-pseudo-classes].
 
-Servo [extends][selector-impl-ext] that trait in order to allow a few more
+Servo extends the selector implementation trait in order to allow a few more
 things to be shared between Stylo and Servo.
 
 The main Servo implementation (the one that is used in regular builds) is
@@ -31,34 +30,30 @@ traits involved.
 Style's [`dom` traits][style-dom-traits] (`TDocument`, `TElement`, `TNode`,
 `TRestyleDamage`) are the main "wall" between layout and style.
 
-Layout's [`wrapper`][layout-wrapper] module is the one that makes sure that
+Layout's [`wrapper`][layout-wrapper] module makes sure that
 layout traits have the required traits implemented.
 
 <a name="stylist"></a>
 ## The Stylist
 
-The [`stylist`][stylist] structure is the one that holds all the selectors and
+The [`stylist`][stylist] structure holds all the selectors and
 device characteristics for a given document.
 
-The stylesheets' CSS rules are converted into [`Rule`][selectors-rule]s, and
+The stylesheets' CSS rules are converted into [`Rule`][selectors-rule]s.
-introduced in a [`SelectorMap`][selectors-selectormap] depending on the
+They are then introduced in a [`SelectorMap`][selectors-selectormap] depending
-pseudo-element (see [`PerPseudoElementSelectorMap`][per-pseudo-selectormap]),
+on the pseudo-element (see [`PerPseudoElementSelectorMap`][per-pseudo-selectormap]),
 stylesheet origin (see [`PerOriginSelectorMap`][per-origin-selectormap]), and
 priority (see the `normal` and `important` fields in
 [`PerOriginSelectorMap`][per-origin-selectormap]).
 
 This structure is effectively created once per [pipeline][docs-pipeline], in the
-LayoutThread corresponding to that pipeline.
+corresponding LayoutThread.
 
 <a name="properties"></a>
 ## The `properties` module
 
-The [properties module][properties-module] is a mako template where all the
+The [properties module][properties-module] is a mako template. Its complexity is derived 
-properties, computed value computation and cascading logic resides.
+from the code that stores properties, [`cascade` function][properties-cascade-fn] and computation logic of the returned value which is exposed in the main function.
-
-It's a complex template with a **lot** of code, but the main function it exposes
-is the [`cascade` function][properties-cascade-fn], which performs all the
-computation.
 
 <a name="pseudo-elements"></a>
 ## Pseudo-Element resolution