go.mod: bump golang.org/x/tools from 0.19.0 to 0.20.0 (#34)

Bumps [golang.org/x/tools](https://github.com/golang/tools) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/golang/tools/releases)
- [Commits](golang/tools@v0.19.0...v0.20.0)

---
updated-dependencies:
- dependency-name: golang.org/x/tools
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/google/go-cmp v0.6.0
 	github.com/gorilla/feeds v1.1.2
 	github.com/russross/blackfriday/v2 v2.1.0
-	golang.org/x/tools v0.19.0
+	golang.org/x/tools v0.20.0
 )
 
-require golang.org/x/sys v0.18.0 // indirect
+require golang.org/x/sys v0.19.0 // indirect

go.sum

@@ -12,7 +12,7 @@ github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZV
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
-golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/tools v0.19.0 h1:tfGCXNR1OsFG+sVdLAitlpjAvD/I6dHDKnYrpEZUHkw=
-golang.org/x/tools v0.19.0/go.mod h1:qoJWxmGSIBmAeriMx19ogtrEPrGtDbPK634QFIcLAhc=
+golang.org/x/sys v0.19.0 h1:q5f1RH2jigJ1MoAWp2KTp3gm5zAGFUTarQZ5U386+4o=
+golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/tools v0.20.0 h1:hz/CVckiOxybQvFw6h7b/q80NTr9IUQb4s1IIzW7KNY=
+golang.org/x/tools v0.20.0/go.mod h1:WvitBU7JJf6A4jOdg4S1tviW9bhUxkgeCui/0JHctQg=