portico-css: Style codeblocks to look neater.
portico-css: Style codeblocks to look neater.

The currrent css of codeblocks left too much empty space between
the lines as well as indented the first character of a codeblock
slightly towards the right.

This commit fixes both of these, thus making codeblocks look closer
to what someone would expect codeblocks to look like in their text
editor.

synicalsyntax/zulip,andersk/zulip,rht/zulip,synicalsyntax/zulip,synicalsyntax/zulip,brainwane/zulip,punchagan/zulip,kou/zulip,rht/zulip,hackerkid/zulip,andersk/zulip,showell/zulip,hackerkid/zulip,timabbott/zulip,rht/zulip,hackerkid/zulip,eeshangarg/zulip,timabbott/zulip,showell/zulip,eeshangarg/zulip,andersk/zulip,rht/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,showell/zulip,timabbott/zulip,synicalsyntax/zulip,punchagan/zulip,rht/zulip,eeshangarg/zulip,shubhamdhama/zulip,zulip/zulip,shubhamdhama/zulip,shubhamdhama/zulip,kou/zulip,zulip/zulip,synicalsyntax/zulip,shubhamdhama/zulip,showell/zulip,kou/zulip,kou/zulip,andersk/zulip,punchagan/zulip,timabbott/zulip,rht/zulip,andersk/zulip,andersk/zulip,hackerkid/zulip,hackerkid/zulip,punchagan/zulip,punchagan/zulip,eeshangarg/zulip,shubhamdhama/zulip,timabbott/zulip,eeshangarg/zulip,shubhamdhama/zulip,brainwane/zulip,zulip/zulip,brainwane/zulip,brainwane/zulip,kou/zulip,brainwane/zulip,showell/zulip,timabbott/zulip,zulip/zulip,brainwane/zulip,rht/zulip,punchagan/zulip,punchagan/zulip,zulip/zulip,hackerkid/zulip,brainwane/zulip,kou/zulip,showell/zulip,zulip/zulip,shubhamdhama/zulip,hackerkid/zulip,synicalsyntax/zulip,timabbott/zulip,zulip/zulip,showell/zulip,eeshangarg/zulip,synicalsyntax/zulip