cmd/present: Fix indentation in styles.css
cmd/present: Fix indentation in styles.css

No functional changes.

Also adds a newline to the end of the file, for compatibility with
`cat(1)` and `vim(1)`. See also:

https://gcc.gnu.org/ml/gcc/2003-11/msg01568.html

Change-Id: I4fc7ac64ad7c4b4d9c2be7296cb8b612e0becef2
Reviewed-on: https://go-review.googlesource.com/2106
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/tools,matryer/tools,runcom/tools,jdhenke/tools,springning/tools,golang/tools,cmars/tools,nicot/tools,maddyonline/tools,glasser/golang-tools,josharian/tools,glasser/golang-tools,runcom/tools,argandas/tools,4ad/tools,syreclabs/go-tools,argandas/tools,dmitris/tools,dmitris/tools,magiccao/tools,cw2018/tools,syreclabs/go-tools,nicot/tools,argandas/tools,cw2018/tools,syreclabs/go-tools,cw2018/tools,runcom/tools,cmars/tools,springning/tools,cw2018/tools,jdhenke/tools,golang/tools,maddyonline/tools,magiccao/tools,argandas/tools,springning/tools,cmars/tools,sshetty10/tools,josharian/tools,dmitris/tools,golang/tools,sshetty10/tools,nicot/tools,josharian/tools,nicot/tools,cmars/tools,springning/tools,4ad/tools,matryer/tools,josharian/tools,jdhenke/tools,dmitris/tools,magiccao/tools,sshetty10/tools,maddyonline/tools,glasser/golang-tools,syreclabs/go-tools,runcom/tools,syreclabs/go-tools,syreclabs/go-tools,matryer/tools,golang/tools,jdhenke/tools,4ad/tools,glasser/golang-tools,maddyonline/tools,matryer/tools,magiccao/tools,sshetty10/tools