Is my Dell Upgradeable to SSD?

Solution
Any laptop with a 2.5" SATA-based HDD can be "upgraded" with a 2.5" SATA-based SSD

I don't see the exact spec of your laptop in the link, just the product line - but from what I can find, you're looking at a 6th Gen Core laptop..... so absolutely, a SATA3 SSD could be swapped in for the HDD currently in there.

I'd suggest looking to a minimum of 240GB, potentially greater, depending on your use-case.

PCPartPicker part list / Price breakdown by merchant

Storage: SanDisk - SSD PLUS 240GB 2.5" Solid State Drive ($69.50 @ B&H)
Total: $69.50
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-01-03 12:05 EST-0500
Any laptop with a 2.5" SATA-based HDD can be "upgraded" with a 2.5" SATA-based SSD

I don't see the exact spec of your laptop in the link, just the product line - but from what I can find, you're looking at a 6th Gen Core laptop..... so absolutely, a SATA3 SSD could be swapped in for the HDD currently in there.

I'd suggest looking to a minimum of 240GB, potentially greater, depending on your use-case.

PCPartPicker part list / Price breakdown by merchant

Storage: SanDisk - SSD PLUS 240GB 2.5" Solid State Drive ($69.50 @ B&H)
Total: $69.50
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-01-03 12:05 EST-0500
 
Solution
You are good.
I have replaced the hard drive with a ssd on every laptop I own.
The easy way is to buy a Samsung 850 evo 2.5" drive of suitable capacity.
Samsung has a free Windows C drive mover for their ssd devices.
Here is the manual which tells how to do it:
http://downloadcenter.samsung.com/content/SW/201711/20171106140405335/Samsung_SSD_Data_Migration_User_Manual_ENG_v3_1.pdf
You attach the new ssd via a usb port. You may need a usb to sata adapter cable, about $15.
When the copy is done, replace the hard drive in your laptop with the ssd.
Here is a youtube video of the process for your laptop:
https://www.youtube.com/watch?v=gwgQAmP_So8
You need only to go so far as to uncover the sata hard drive and replace it.
 
Yes, it is upgradeable to any 7mm height 2.5 inch SSD.