make NEWS.md link style more consistent (#51978)

Minor PR to make the PR link punctuation a bit more consistent in the
NEWS file, and adds a couple of missing PR links.

NEWS.md

@@ -6,7 +6,7 @@ New language features
 * `public` is a new keyword. Symbols marked with `public` are considered public
  API. Symbols marked with `export` are now also treated as public API. The
  difference between `public` and `export` is that `public` names do not become
- available when `using` a package/module. ([#50105])
+ available when `using` a package/module ([#50105]).
 * `ScopedValue` implement dynamic scope with inheritance across tasks ([#50958]).
 * The new macro `Base.Cartesian.@ncallkw` is analogous to `Base.Cartesian.@ncall`,
  but allows to add keyword arguments to the function call ([#51501]).
@@ -34,7 +34,7 @@ Command-line option changes
 (i.e. using `julia script.jl` or `julia -e expr`), julia will subsequently run the `Main.main` function automatically.
 This is intended to unify script and compilation workflows, where code loading may happen
 in the compiler and execution of `Main.main` may happen in the resulting executable. For interactive use, there is no semantic
-difference between defining a `main` function and executing the code directly at the end of the script. ([50974])
+difference between defining a `main` function and executing the code directly at the end of the script ([50974]).
 
 Multi-threading changes
 -----------------------
@@ -46,8 +46,8 @@ New library functions
 ---------------------
 
 * The new `Libc.mkfifo` function wraps the `mkfifo` C function on Unix platforms ([#34587]).
-* `hardlink(src, dst)` can be used to create hard links. ([#41639])
-* `diskstat(path=pwd())` can be used to return statistics about the disk. ([#42248])
+* `hardlink(src, dst)` can be used to create hard links ([#41639]).
+* `diskstat(path=pwd())` can be used to return statistics about the disk ([#42248]).
 * `copyuntil(out, io, delim)` and `copyline(out, io)` copy data into an `out::IO` stream ([#48273]).
 * `eachrsplit(string, pattern)` iterates split substrings right to left.
 
@@ -61,14 +61,14 @@ Standard library changes
 
 #### StyledStrings
 
-* A new standard library for handling styling in a more comprehensive and structured way.
+* A new standard library for handling styling in a more comprehensive and structured way ([#49586]).
 * The new `Faces` struct serves as a container for text styling information
  (think typeface, as well as color and decoration), and comes with a framework
  to provide a convenient, extensible (via `addface!`), and customisable (with a
  user's `Faces.toml` and `loadfaces!`) approach to
- styled content.
+ styled content ([#49586]).
 * The new `@styled_str` string macro provides a convenient way of creating a
- `AnnotatedString` with various faces or other attributes applied.
+ `AnnotatedString` with various faces or other attributes applied ([#49586]).
 
 #### Package Manager
 
@@ -88,7 +88,7 @@ Standard library changes
 #### REPL
 
 * Tab complete hints now show in lighter text while typing in the repl. To disable
- set `Base.active_repl.options.hint_tab_completes = false` ([#51229])
+ set `Base.active_repl.options.hint_tab_completes = false` ([#51229]).
 * Meta-M with an empty prompt now returns the contextual module of the REPL to `Main`.
 
 #### SuiteSparse
@@ -102,7 +102,7 @@ Standard library changes
 
 #### Statistics
 
-* Statistics is now an upgradeable standard library.([#46501])
+* Statistics is now an upgradeable standard library ([#46501]).
 
 #### Distributed
 
@@ -122,13 +122,13 @@ Deprecated or removed
 
 External dependencies
 ---------------------
-* `tput` is no longer called to check terminal capabilities, it has been replaced with a pure-Julia terminfo parser.
+* `tput` is no longer called to check terminal capabilities, it has been replaced with a pure-Julia terminfo parser ([#50797]).
 
 Tooling Improvements
 --------------------
 
 * CI now performs limited automatic typo detection on all PRs. If you merge a PR with a
  failing typo CI check, then the reported typos will be automatically ignored in future CI
- runs on PRs that edit those same files. ([#51704])
+ runs on PRs that edit those same files ([#51704]).
 
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