docs: Reorganize readme (#1093)

* reorganize and optimize for configuration options
* remove outdated docs and point more to the preset configs
* add a Coverage thresholds section
* add the skip-full option to the table because it's interesting
* move nyc instrument link closer to the advanced features
* rework installation section
* move Source map info towards the bottom
* remove incorrect sections and formatting
* documents interaction between --require and --all
* add Combining multiple runs section
* remove old custom require hooks section

.github/ISSUE_TEMPLATE.md

@@ -18,7 +18,8 @@ create a basic `nyc-bug-demo` repository and link to that please [mandatory].
 
 ## Environment Information
 <!--
-[mandatory] run the following script: npx envinfo@latest --preset nyc
+[mandatory] run the following script: 
+  npx envinfo@latest --preset nyc
 -->
 ```
 # paste the output here