Make documentation more consistent with Vim's own :help (#4840)

* Prefix user-defined commands with colons

This is consistent with Vim's own :help pages.

* Remove dot hack

Now that we have `:ALEInfo` and `ALEInfo`, we don't need `ALEInfo.` any
more to disambiguate them.

* Use colons in references

* Use angle brackets for command arguments

* Use `:Command` for command references

* Use a non-command reference for tsserver

* Prefix highlight references with hl-

* Fix some references into Vim's own :help

E.g. location-list or +features

* Misc hotlink improvements

* Undo previous changes to tsserver

Just leave it in backticks - even though I don't like it.

* Use bars for a command for consistency

* Append hotlinks to hl-groups

Remove minuses to make tables look more like in Vim's own :help

* Prefix features with +

* Provide full hotlink to ale.txt

* Fix double pipe typo

* Capitalize Error highlight

There seems to be no hotlink in Vim's own documentation for this.
I would have expected *hl-Error* - no such thing :-(

* Right align tags to col 79

doc/ale-development.txt

@@ -49,10 +49,10 @@ changes should be preceded by a deprecation phase complete with warnings.
 Changes required for security may be an exception.
 
 ALE supports Vim 8 and above, and NeoVim 0.6.0 or newer. These are the
-earliest versions of Vim and NeoVim which support |job|, |timer|, |closure|,
-and |lambda| features. All ALE code should be written so it is compatible with
-these versions of Vim, or with version checks so particular features can
-degrade or fail gracefully.
+earliest versions of Vim and NeoVim which support |+job|, |+timer|,
+|+closure|, and |+lambda| features. All ALE code should be written so it is
+compatible with these versions of Vim, or with version checks so particular
+features can degrade or fail gracefully.
 
 Just about everything should be documented and covered with tests.
 
@@ -486,7 +486,7 @@ last minor version.
 
 Generally ALE releases hit a major version only when there are breaking
 changes to a public ALE setting or function. A "public" setting or function is
-defined as any setting or function documented in the `:help` |ale| text file.
+defined as any setting or function documented in the `:help` |ale.txt| file.
 Major ALE versions ought to be so rare that they only come once a year at
 most. ALE should not typically introduce any breaking changes.