Revise README

- Removed extra whitespace.
- Fixed markup errors with `.
- Spelling.
- Link Github releases.
- Link to git-filter-repo.

README.md

@@ -1,7 +1,7 @@
 # TK1 PCBA
 
 This repository contains the PCB design and manufacturing files for
-the flexible Open Source security key, TKey (TK1). 
+the flexible Open Source security key, TKey (TK1).
 
 This is part of a larger project that includes firmware and FPGA
 designs, which are housed at
@@ -18,12 +18,13 @@ For more general information about the TKey see,
     - tk1, under hw
     - mta1-usb-v1, under prototypes
     - mta1-usb-dev, under prototypes
-- Manufacturing outputs (Gerber files, BOM, etc.), under releases
+- Manufacturing outputs (Gerber files, BOM, etc.), under [Github
+  releases](https://github.com/tillitis/tk1-pcba/releases)
 - Libraries, under hw/lib
 
 The earlier version of TK1, such as the `mta1-usb-v1` and
 `mta1-usb-dev`, that can be found under `prototypes/` are kept for
-historical reasons. TK1 is the only version that is maintaned and
+historical reasons. TK1 is the only version that is maintained and
 developed.
 
 ## Getting started
@@ -43,7 +44,7 @@ The KiBot flow can be run locally using the Make target
 make run-kibot
 ```
 
-the prerequisits are `Podman`. `Docker can also be used`, see the
+the prerequisits are `Podman`. `Docker` can also be used, see the
 Makefile for details.
 
 
@@ -75,18 +76,22 @@ The [CERN-OHL-S user guide](/User-guide-CERN-OHL-S.txt) is included to
 make it easier to follow the license, both as a Licensor or a Licensee.
 
 ## History
-This repo is created by filtering out relevant commits and files from
-the tillitis/tillits-key1 repo.
+This repo was created by filtering out relevant commits and files from
+the [tillitis/tillits-key1](https://github.com/tillitis/tillitis-key1)
+repo.
 
-The filtering removes all files and commits that are not related to
-the tk1 hardware. This is done using `git-filter-repo`. To replicate
-the results up until commit `6c7629c` in this repo, checkout commit
-`354aecb` in tillitis/tillitis-key1 and run `git-filter-repo --path
-hw/boards/mta1-library --path hw/boards/mta1-usb-dev --path
-hw/boards/mta1-usb-v1 --path hw/boards/tk1`.
+The filtering removed all files and commits that weren't related to
+the tk1 hardware. This was done using
+[git-filter-repo](https://github.com/newren/git-filter-repo).
+
+To replicate the results up until commit `6c7629c` in this repo,
+checkout commit `354aecb` in `tillitis/tillitis-key1` and run
+`git-filter-repo --path hw/boards/mta1-library --path
+hw/boards/mta1-usb-dev --path hw/boards/mta1-usb-v1 --path
+hw/boards/tk1`.
 
 All filtered commits have intact date, author, and code. Some
 unrelated files are removed from some commits, but the commit messages
 are left unchanged. Commit sha, tags and signatures are new. For
 complete history, please see tillitis/tillitis-key1 from commit
-354aecb` and earlier.
+`354aecb` and earlier.