website: full-source-bootstrap: Fix typos.

* website/posts/full-source-bootstrap.md: Fix typos.

website/posts/full-source-bootstrap.md

@@ -10,14 +10,14 @@ graph of more than 22,000 nodes _rooted in a 357-byte program_—something
 that had never been achieved, to our knowledge, since the birth of Unix.
 
 We refer to this as the _Full-Source Bootstrap_.  In this post, we
-explain what this means concretely.  This a major milestone—if not _the_
+explain what this means concretely.  This is a major milestone—if not _the_
 major milestone—in our quest for building _everything_ from source, all
 the way down.
 
 How did we get there, and why?  In [two previous
 ](https://guix.gnu.org/blog/2020/guix-further-reduces-bootstrap-seed-to-25/)
 [blog
-post](https://guix.gnu.org/blog/2019/guix-reduces-bootstrap-seed-by-50/),
+posts](https://guix.gnu.org/blog/2019/guix-reduces-bootstrap-seed-by-50/),
 we elaborated on why this reduction and bootstrappability in general
 is so important.
 
@@ -74,10 +74,10 @@ Orians first builds hex0 and then all the way up: hex1, catm, hex2,
 M0, cc_x86, M1, M2, get_machine (that's all of MesCC-Tools), and
 finally [M2-Planet](https://github.com/oriansj/m2-planet).
 
-The new [GNU Mes](https://gnu.org/s/mes) v0.24 release can be built
-with M2-Planet.  This time with only a [remarkably small change]
-(https://issues.guix.gnu.org/55227), the bottom of the package graph
-now looks like this (woohoo!):
+The new [GNU Mes](https://gnu.org/s/mes) v0.24 release can be built with
+M2-Planet.  This time with only a [remarkably small
+change](https://issues.guix.gnu.org/55227), the bottom of the package
+graph now looks like this (woohoo!):
 
 ```
                               gcc-mesboot (4.9.4)
@@ -141,7 +141,7 @@ sometimes there are no obvious answers, for example:
 - In 2013, the year that [Reproducible
   Builds](https://reproducible-builds.org) started to gain some
   traction, the GNU Compiler Collection [released
-  gcc-4.8.0](http://gcc.gnu.org/gcc-4.8/changes.html),
+  version 4.8.0](http://gcc.gnu.org/gcc-4.8/changes.html),
   making C++ a build requirement, and
 
 - Even more recently (2018), the GNU C Library [glibc-2.28 adds Python
@@ -196,7 +196,7 @@ build GCC 4.6.5; meanwhile, Ekaitz Zarraga
 support from the latest [tcc](https://www.tinycc.org) to our
 [bootstrappable-tcc](https://gitlab.com/janneke/tinycc).
 
-## Outlook
+### Outlook
 
 The full-source bootstrap was once deemed impossible.  Yet, here we are,
 building the foundations of a GNU/Linux distro entirely from source, a
@@ -209,7 +209,7 @@ Linux kernel?  The good news is that the bootstrappable community has
 grown a lot, from two people six years ago there are now around 100
 people in the `#bootstrappable` IRC channel.  Interesting times ahead!
 
-#### About Bootstrappable Builds and GNU Mes
+#### About Bootstrappable Builds and GNU Mes
 
 Software is bootstrappable when it does not depend on a binary seed
 that cannot be built from source.  Software that is not