Wiki/Requirements: improve readability

* Highlight (bold) PHP extension names
* Force a few long bullet points to display as multiple lines.

Author: jrfnl

wiki/Requirements.md

@@ -1,22 +1,25 @@
-PHP_CodeSniffer 4.x requires PHP 7.2.0 or greater.
+PHP_CodeSniffer 4.x requires **PHP 7.2.0 or greater**.  
 _Prior to PHP_CodeSniffer 4.0.0, the minimum PHP requirement was 5.4.0._
 
 Additionally, PHP_CodeSniffer requires the following PHP extensions to be enabled:
-- [Tokenizer][tokenizer]: used by the core tokenizer to process PHP files
-- [SimpleXML][simplexml]: used to process ruleset XML files
-- [XMLWriter][xmlwriter]: used to create some report formats
-- [libxml]: required by the SimpleXML and XMLWriter extensions
+- **[Tokenizer][tokenizer]**: used by the core tokenizer to process PHP files
+- **[SimpleXML][simplexml]**: used to process ruleset XML files
+- **[XMLWriter][xmlwriter]**: used to create some report formats
+- **[libxml]**: required by the SimpleXML and XMLWriter extensions
 
-The following PHP extensions are not required, but are strongly recommended:
-- [DOM][dom]: used for displaying the sniff documentation via the `--generator=...` option.
-- [iconv]: used for accurate character length calculation in files containing multibyte characters. Without this extension, some sniffs, like `Generic.Files.LineLength`, may report incorrect results for lines containing non-ASCII characters, as PHP_CodeSniffer will fall back to byte-based length calculations. Additionally, the following reports may not work correctly without this extension: [Checkstyle][wiki-report-checkstyle], [JUnit][wiki-report-junit] and [XML][wiki-report-xml].
-- [json]: required for the cache functionality, as well as for the [JSON report][wiki-report-json] output.
-- [PCNTL][pcntl]: required for parallel processing via the `--parallel` CLI option. Without this extension, PHP_CodeSniffer will not be able to check multiple files simultaneously.
+The following PHP extensions are not required, but are **_strongly recommended_**:
+- **[DOM][dom]**: used for displaying the sniff documentation via the `--generator=...` option.
+- **[iconv]**: used for accurate character length calculation in files containing multibyte characters.  
+    Without this extension, some sniffs, like `Generic.Files.LineLength`, may report incorrect results for lines containing non-ASCII characters, as PHP_CodeSniffer will fall back to byte-based length calculations.  
+    Additionally, the following reports may not work correctly without this extension: [Checkstyle][wiki-report-checkstyle], [JUnit][wiki-report-junit] and [XML][wiki-report-xml].
+- **[json]**: required for the cache functionality, as well as for the [JSON report][wiki-report-json] output.
+- **[PCNTL][pcntl]**: required for parallel processing via the `--parallel` CLI option.  
+    Without this extension, PHP_CodeSniffer will not be able to check multiple files simultaneously.
 
 Individual sniffs may have additional requirements such as external applications and scripts. See the [Configuration Options][wiki-config] manual page for a list of these requirements.
 
 > [!WARNING]
-> The [gRPC PHP extension][grpc] is known to cause PHP_CodeSniffer to hang when running with parallel processing enabled. If the gRPC extension is loaded, either do not use the `--parallel` CLI option or configure the extension's ini settings as follows:
+> The **[gRPC PHP extension][grpc]** is known to cause PHP_CodeSniffer to hang when running with parallel processing enabled. If the gRPC extension is loaded, either do not use the `--parallel` CLI option or configure the extension's ini settings as follows:
 > ```text
 > phpcs -d grpc.enable_fork_support=1 -d grpc.poll_strategy=epoll1 [other options] <file|directory>
 > ```