Browsing Brazilian Portuguese translation

ACCOMPLISHMENT: Ubuntu Core Developer ('summary' field)
.
ORIGINAL TRANSLATION:
An Ubuntu Core Developer is responsible for packaging and resolving issues in the <tt>main</tt> archive. This includes some of the most critical software that is part of an Ubuntu system, and the pieces that ship in a default Ubuntu installation.
.
----- TRANSLATION INSTRUCTIONS -----
Introduce the accomplishment, explain what the different concepts are that are involved, and provide guidance on how to accomplish it.
NOTE: Break this into paragraphs by putting each paragraph on a new line.
FORMATTING ALLOWED: <i> <strong> <tt>